Fix email delivery issues for error code 550 5.7.1 in Exchange Online (2022)

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Important

Mail flow rules are now available in the new Exchange admin center. Try it now!

It's frustrating when you get an error after sending an email message. This topic describes what you can do if you see error code 5.7.1 in a non-delivery report (also known as an NDR, bounce message, delivery status notification, or DSN). This information also applies to error codes 5.7.0 through 5.7.999.

Fix email delivery issues for error code 550 5.7.1 in Exchange Online (1)I got this bounce message. How do I fix this issue?Fix email delivery issues for error code 550 5.7.1 in Exchange Online (2)I'm an email admin. How can I fix this issue?

This information also applies to error codes 5.7.0 through 5.7.999 in Exchange Online and Microsoft 365 or Office 365. There can be several causes for dsn error code 5.7.1, for which solutions are provided later in this topic.

Why did I get this bounce message?

Typically, this error indicates a security setting in your organization or the recipient's organization is preventing your message from reaching the recipient. For example:

  • You don't have permission to send to the recipient.
  • The recipient is a group, and you don't have permission to send to the group or one of its subgroups.
  • You don't have permission to send email through an email server that's between you and the recipient.
  • Your message was routed to the wrong email server.

I got this bounce message. How do I fix this issue?

Typically, you can't fix the problem yourself. You'll need the recipient or the recipient's email admin to fix the configuration on their end. However, here are some steps that you can try:

  • If the recipient is external (outside of your organization): Contact the recipient (by phone, in person, etc.) and ask them to tell their email admin about your email delivery problem. Their email admin might need to reconfigure the recipient's mailbox so it accepts email from you.

  • If the recipient is an internal group: You might not have permission to send to the group or to one of its subgroups. In this case, the NDR will include the names of the restricted groups that you don't have permission to send to. Ask the owner of the restricted group to grant you permission to send messages to the group. If you don't know the group's owner, you can find it in Outlook or Outlook on the web (formerly known as Outlook Web App) by doing the following steps:

    • Outlook: Select the NDR, double-click the group name on the To line, and then choose Contact.
    • Outlook on the web: Select the NDR, choose the group name on the To line, and then choose Owner.
  • If you're sending to a large distribution group: Groups with more than 5,000 members have the following restrictions automatically applied to them:

    • Messages sent to the group require approval by a moderator.
    • Large messages can't be sent to the group. However, senders of large messages will receive a different NDR. For more information about large messages, see Distribution group limits.

    To resolve the issue, join the group, or ask the group's owner or moderator to approve your message. Refer them to the I'm the owner of a restricted group. What can I do? section later in this topic.

    (Video) Email Undeliverable | Error code 5.1.10 in Office 365 | Update accepted domain settings | Exchange

If none of the previous steps apply or solve your issue, contact the recipient's email administrator, and refer them to the I'm an email admin. How can I fix this issue? section later in this topic.

I'm the owner of a restricted group. What can I do?

If a message sender received this NDR when they attempted to send a message to your group, and you want them to successfully send messages to your group, try one of the following steps:

I'm an email admin. How can I fix this issue?

If the steps in the earlier sections don't solve the issue for the sender, the solution likely requires action by the recipient's email admin. The scenarios and solutions are described in this section.

The sender is external (outside your organization)

If only this recipient is having difficulty accepting messages from external senders, configure the recipient or your email servers to accept messages from external or anonymous senders.

The recipient is a public folder in your Exchange Online organization

When the recipient is a mail-enabled public folder in your Exchange Online organization, an external sender will receive an NDR with the following error code:

Remote Server returned '<xxxxxxxx> #5.7.1 smtp;550 5.7.1 RESOLVER.RST.AuthRequired; authentication required [Stage: CreateMessage]'

To configure the public folder to accept messages from external senders, follow these steps:

New EAC

  1. Open the Exchange admin center (EAC). For more information, see Exchange admin center in Exchange Online.

    (Video) SOLVED 550 5.7.520 Access Denied Organization Does Not Allow External Forwarding

  2. Go to Public folders > Public folders.

  3. Choose a public folder from the list, and then click Edit Fix email delivery issues for error code 550 5.7.1 in Exchange Online (3).

    Fix email delivery issues for error code 550 5.7.1 in Exchange Online (4)

  4. Click Mail flow settings.

  5. Under Message Delivery Restrictions > Accept messages from, perform the following tasks:

    • Clear the check box for Require that all senders are authenticated.
    • Select All senders.

    Fix email delivery issues for error code 550 5.7.1 in Exchange Online (5)

  6. Click Save.

Classic EAC

  1. Open the Exchange admin center (EAC). For more information, see exchange admin center in exchange online.

  2. In the EAC, go to Public folders > Public folders > select the public folder from the list, and then click Edit Fix email delivery issues for error code 550 5.7.1 in Exchange Online (6)

    Fix email delivery issues for error code 550 5.7.1 in Exchange Online (7)

  3. In the public folder properties dialog box that opens, go to Mail flow settings, and configure the following settings in the Accept messages from section:

    • Clear the check box for Require that all senders are authenticated.
    • Select All senders.

    Fix email delivery issues for error code 550 5.7.1 in Exchange Online (8)

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  4. Click Save.

The sender is external and their source IP address is on Microsoft's blocklist

In this case, the NDR the sender receives would include information in the Diagnostics for administrators section similar to the following information:

5.7.1 Service unavailable; Client host [xxx.xxx.xxx.xxx] blocked using Blocklist 1; To request removal from this list please forward this message to delist@messaging.microsoft.com

To remove the restriction on the sender's source email system, forward the NDR message to delist@messaging.microsoft.com. Also see Use the delist portal to remove yourself from the blocked senders list.

Your domain isn't fully enrolled in Microsoft 365 or Office 365

If your domain isn't fully enrolled in Microsoft 365 or Office 365, try the following steps:

  • Verify your domain appears as Healthy in the Microsoft 365 admin center at Settings > Domains.
  • For information about adding your domain to Microsoft 365 or Office 365, see Add a domain to Microsoft 365.
  • To troubleshoot domain verification issues, see Microsoft Knowledge Base article KB2515404.

Your domain's MX record has a problem

If you have an incorrect MX record, try the following steps:

  1. Check the sender and recipient domains for incorrect or stale MX records by using the Advanced diagnostics > Exchange Online test in the Microsoft Support and Recovery Assistant. For more information about the Support and Recovery Assistant, see About the Microsoft Support and Recovery Assistant.

  2. Check with your domain registrar or DNS hosting service to verify the MX record for your domain is correct. The MX record for a domain that's enrolled in Exchange Online uses the syntax <domain\ >.mail.protection.outlook.com.

  3. Verify Inbound SMTP Email and Outbound SMTP Email at Office 365 > Mail Flow Configuration in the Microsoft Remote Connectivity Analyzer.

  4. Verify you have only one MX record configured for your domain. Microsoft doesn't support using more than one MX record for a domain that's enrolled in Exchange Online.

Your domain's SPF record has a problem

The Sender Policy Framework (SPF) record for your domain might be incomplete, and might not include all email sources for your domain. For more information, see Set up SPF to help prevent spoofing.

Hybrid configuration issues

  • If your domain is part of a hybrid deployment between on-premises Exchange and Exchange Online, the Hybrid Configuration Wizard should automatically configure the required connectors for mail flow. Even so, you can use the steps in this section to verify the connector settings.

    (Video) 550 Authentication - Undeliverable email

    1. Open the Microsoft 365 admin center at https://portal.microsoftonline.com, and click Admin > Exchange.

    2. In the Exchange admin center, click Mail Flow > Connectors. Select the connector that's used for hybrid, and choose Edit. Verify the following information:

      • Delivery: If Route mail through smart hosts is selected, confirm the correct IP address or FQDN is specified. If MX record associated with the recipient domain is selected, confirm the MX record for the domain points to the correct mail server.

        You can test your MX record and your ability to send mail from your Exchange Online organization by using the Outbound SMTP Email test in the Microsoft Remote Connectivity Analyzer.

      • Scope: If you need to route inbound internet mail to your on-premises Exchange organization, Domains need to include all email domains that are used in your on-premises organization. You can use the value asterisk (*) to also route all outbound internet mail through the on-premises organization.

    If the connectors are configured incorrectly, your Exchange administrator needs to rerun the Hybrid Configuration Wizard in the on-premises Exchange organization.

  • If you disable an on-premises Active Directory account, you'll get the following error message:

    Your message couldn't be delivered to the recipient because you don't have permission to send to it.Ask the recipient's email admin to add you to the accept list for the recipient.For more information, see DSN 5.7.129 Errors in Exchange Online and Microsoft 365 or Office 365.

    To cease all communication with the Exchange Online mailbox, you need to delete the on-premises user account instead of disabling it.

    Another solution would be to remove the license, but then you would need to create a mail flow rule (also known as a transport rule) to prevent the user from receiving email messages. Otherwise, the user would continue to receive messages for about 30 days after removal of the license.

    Consider this scenario as part of the workflow for disabling a user on Exchange Online.

Still need help?

(Video) 554 Delivery Error Yahoo Email | Error Code 554 | - Customer Supports Service ®

See also

Email non-delivery reports in Exchange Online

FAQs

How to Fix 550 5. 7 1 relaying denied? ›

It's likely that the email server isn't correctly set up to receive and relay messages from your organization. To fix this issue, forward this non-delivery report (NDR) to your email admin. The sender's message was routed to an email server outside Microsoft 365 that returned an error that it can't relay the message.

What is status code 5. 7 1? ›

1. You might see this error if: You don't have permission to send to the recipient. You don't have permission to send to the distribution group or subgroups.

Can t send mail All recipients were rejected 550 5. 7 1? ›

A 550 5.7. 1 commonly refers to the IP sending the email, currently blocked from the recipient's email service. It is normally blocked because the IP was used to send spam to the recipient's IP at one point in time.

Can't send mail all recipients were rejected 550 5.7 1 relaying denied? ›

This error message means the recipient email address you entered is invalid or doesn't exist in the destination domain. It happens either because of email address typos or due to a misconfiguration of the recipient's server.

Why does my email Say Access Denied? ›

The most common reasons for this error are: The sender did not authenticate to the outgoing mail server due to some misconfigurations. The recipient's server has determined the sender's server to be a source of spam, or that it had failed security checks.

How do I fix relaying denied? ›

Dealing with “Relaying Denied”

Double-check your own email program's configuration — specifically its SMTP settings — making sure you're following your ISP's instructions. Double-check the email address you're sending to, making sure that it's correct. Try again later.

How do I fix 550 authentication required? ›

Open MS Outlook Express >> go to Tools menu >> Accounts >> Highlight an email account >> Properties >> Server tab >> Under the Outgoing Mail Server >> now check the “My server requires authentication” checkbox >> Settings button. Verify that “Use same setting as my incoming mail server” is selected.

What is 550 5.7 1 Your access to submit messages to this e mail system has been rejected? ›

If Your NDR Description says 550 5.7. 1 Your message can't be delivered because one or more recipients are blocked by your organization's tenant recipient block policy. AS(8910) , the Email address or domain must be part of blocked domains & addresses under your Organization's Tenant Allow/Block list.

What is a 550 error? ›

Server error "550 this domain is not hosted here" indicates that the recipient address is not found or is inaccessible. Server error 550 or 550 Blocked Error indicates that the recipient is blocking your email on the recipient's email server.

How do you fix 550 5.1 1 The email account that you tried to reach does not exist? ›

Solution 1: Confirm the recipient's email address

It sounds too simple, but the wrong email address is the most common issue that causes 5.1. x errors. Check for correct spelling and send the message again if you find an error in the email address. To resend the message in Outlook, see Resend an email message.

What does 5.7 1 TLS required by recipient mean? ›

July 20, 2021 06:54. If you're receiving this error, it means your email message was sent from a server or domain that is currently listed as a high volume spam source by a reputable global block list.

How do you fix 550 this message was classified as spam and may not be delivered? ›

Solution #1 – Enable SMTP Authentication in Outlook

If you are using the Microsoft Outlook email client, not having SMTP Authentication will cause several points to be added to the spam score. This can cause emails that otherwise would be allowed through to be classified as spam.

How do I enable SMTP authentication? ›

Enable SMTP AUTH for specific mailboxes
  1. Open the Microsoft 365 admin center and go to Users > Active users.
  2. Select the user, and in the flyout that appears, click Mail.
  3. In the Email apps section, click Manage email apps.
  4. Verify the Authenticated SMTP setting: unchecked = disabled, checked = enabled.
5 days ago

How do I enable SMTP authentication in Outlook? ›

Outlook 2013 and 2016
  1. Open your Outlook account.
  2. From the Tools menu, choose Account Settings.
  3. Select your email account from the list, then click Change.
  4. On the Change E-mail Settings window, click More Settings.
  5. Click the Outgoing Server tab, then check the My outgoing server (SMTP) requires authentication option.

How do I fix a relay access denied in Outlook? ›

How to fix Relay Access Denied Error in Mail.
  1. Verify Mail Server Settings and Account Credentials. ...
  2. Enable SMTP User Authentication & Secure Connection. ...
  3. Verify Email Settings with your Email Provider & Scan for Viruses. ...
  4. Check if your Mail Server or your Domain is Listed at SPAM (BLOCK) lists.

How do I fix 550 5.4 1 Recipient address rejected Access denied? ›

Select all mailboxes for public folders that you are using and click on Add to enforce the change, and then click on OK to execute it. Once done, you can re-send the affected email and see if the “550 5.4 1 Recipient Address Rejected access denied” error is fixed.

Why am I getting access denied on this server? ›

Causes For “Access denied on this server” Error

Using a Proxy Server. Cached data on your browsers. Misconfigured browser settings. DNS server unable to resolve the web address.

How do I fix Recipient address rejected? ›

4 Ways To Fix Recipient Address Rejected Error
  1. Use the Correct Recipient Email Address.
  2. Redo DNS Cache.
  3. Request Addition To Whitelist.
  4. Update Exchange Email Settings.
13 Jun 2022

What is server Error 550 on Outlook Express? ›

550 Blocked error or 550 Requested action not taken: mailbox unavailable is an SMTP (Simple Mail Transfer Protocol) error code. Put simply, this message means that the email you sent was blocked by the recipient's email hosting server, and returned to you.

What ports does SMTP use? ›

Which port should you use for SMTP? Ports 25, 465, 587, or 2525 for SMTP have all been considered standard SMTP ports at some point, but only 587 or 2525 really should be considered for modern use.

Is not permitted to relay through this server without 550 authentication exchange? ›

1.1) or Server error: 550 relay not permitted, authentication required / Relay not allowed The most common cause is that authentication is missing in the outgoing mail settings. With outgoing mail, your e-mail address / login and corresponding password are also required.

How do you fix None of the authentication methods supported by this client are supported by your server? ›

Click on File > Account Settings > Account Settings. Select the email account as per the error message, and then click Change. Click More Settings and navigate to the Outgoing tab. Check 'My outgoing server requires authentication' and use same settings as my incoming server.

What does authenticated SMTP access mean? ›

The Authenticated SMTP product allows emails to be sent out from a domain through our outgoing mail servers. Due to the authentication method it uses, it ensures that emails can only be sent from a domain if the sender is using a valid username and password associated with that domain.

What does 550 too many invalid recipients mean? ›

If you are receiving this error it indicates that the email account has been blocked because the account has been sending emails to a large number of invalid addresses. Spammers often send to a large number of invalid recipients.

What does 550 rejected by header based manually blocked senders mean? ›

When you receive an Error 550 Message Rejected (or blocked) when trying to send an email, this means that a spam filter has blocked the message. This error is occurring because your email domain is appearing in a Real-time Blackhole List (RBL).

How do I fix webmail error? ›

How to Fix Email Not Working in Browser Webmail
  1. 1 Restart Your Device. Many basic problems can be solved simply by restarting your device. ...
  2. 2 Make Sure the Internet Connection Works. Open your browser. ...
  3. 3 Clear Browser Cache and Cookies. ...
  4. 4 Check the Status of the Website.

Could not be delivered the problem appears to be recipient email server rejected the message? ›

When you send an email and get an “address rejected” error message, it means the email server can't verify your email address because the SMTP server authentication feature is disabled in your email client. Enable the SMTP server authentication feature in your email client.

What does it mean when a mailbox is unavailable? ›

“Mailbox unavailable” can indicate that your email message failed to deliver for any number of different reasons, ranging from bad email addresses to closed or suspended accounts to quotas having been reached to mail server problems and more.

What is SMTP error while sending mail? ›

SMTP is an internet standard used by mail servers to send and receive email. SMTP error messages help you understand why a message wasn't sent successfully. If incoming or outgoing messages are bouncing, check the bounce messages for an SMTP error code that can help you diagnose the problem.

How do I change SMTP settings in cPanel? ›

In cPanel, navigate to the Email Accounts interface, which you will find in the main page menu's Email section.
  1. Click the “Create” button.
  2. On the next page, select a domain, a username, and a password. ...
  3. On this page, you will find the username and the URL and SMTP port number of the outgoing server.
3 Sept 2020

Can't send mail all recipients were rejected 550 5.1 1 no such user? ›

550 5.1. 1 means that the recipient email server believes that the email address does not exist at the destination domain, and therefore has no way to deliver it. Unless you simply made a typo in the email address, this is not something that you can fix, and must be addressed at the other end.

How do I fix SMTP 550 error? ›

Fortunately, resolving this error can be done quickly and easily. You simply need to configure your email client to send the appropriate credentials. In most email clients, SMTP authentication can be enabled by editing the account configuration and adjusting the Outgoing Server / SMTP settings.

What does Recipient address rejected mean? ›

1 error code in Email non-delivery reports in Exchange Online it suggests: "The mail server that's generating the error doesn't accept mail for the recipient's domain. This error is generally caused by mail server or DNS misconfiguration." To put it simply, the issue is on the recipient end and no on your end.

How do I fix 550 relaying denied? ›

It's likely that the email server isn't correctly set up to receive and relay messages from your organization. To fix this issue, forward this non-delivery report (NDR) to your email admin. The sender's message was routed to an email server outside Microsoft 365 that returned an error that it can't relay the message.

How do you fix 550 administrative prohibition? ›

This error can be resolved by verifying the Verified Senders. If the error message persists with a verified sending domain, have the recipient whitelist our sending IP addresses with their incoming mail server.

Can't connect to SMTP host? ›

Error: SMTP error: could not connect to SMTP host

However, there are some common aspects that you may need to validate before proceeding further. Security Restrictions. Temporary connection issues. Invalid client-side settings.

Can't send mail all recipients were rejected 550 5.7 1 relaying denied? ›

This error message means the recipient email address you entered is invalid or doesn't exist in the destination domain. It happens either because of email address typos or due to a misconfiguration of the recipient's server.

Why are my emails being rejected by server? ›

The recipient (email address) was rejected by the server because it does not allow relaying”. This need not mean you are sending to an incorrect recipient address. If the mail server feels you are trying to relay through it without proper authentication, this error pops up.

How do I check if my email is blacklisted? ›

This is how you can check your email address with MXToolBox: Go to https://mxtoolbox.com/blacklists.aspx. Enter your server IP or domain name and click the “Blacklist Check” button to perform an email blacklist check.

How do I find my SMTP settings in Office 365? ›

Find your Exchange mailbox server settings

In Outlook Web App, on the toolbar, select Settings. > Mail > POP and IMAP. The POP3, IMAP4, and SMTP server name and other settings you may need to enter are listed on the POP and IMAP settings page.

How do I check my SMTP authentication? ›

To test SMTP authentication via telnet:
  1. In a telnet client such as PuTTY, connect to the SMG appliance: telnet <SMG_IP_address> 587.
  2. Greet the mail server: EHLO mailserver.com.
  3. Tell SMG you want to authenticate with it: AUTH LOGIN. ...
  4. Paste the base64 encoded username. ...
  5. Paste the base64 encoded password for the username.
1 Apr 2019

What is the SMTP setting for Office 365? ›

To configure your device or application, connect directly to Microsoft 365 or Office 365 using the SMTP AUTH client submission endpoint smtp.office365.com.
...
How to set up SMTP AUTH client submission.
Device or Application settingValue
Server/smart hostsmtp.office365.com
PortPort 587 (recommended) or port 25
2 more rows
9 Sept 2022

How do I change my SMTP settings? ›

Windows Mail
  1. Start Windows Mail, click the Tools menu at the top of the window and then click Accounts.
  2. Select your account under Mail, and then click on the Properties button.
  3. Go to the Advanced tab, under Outgoing server (SMTP), change port 25 to 587.
  4. Click the OK button to save the changes.

How do I fix SMTP authentication error in Outlook? ›

Ensure that the "E-mail address" is your valid address for this account. Click "Servers" tab. Verify your account name is complete and its password is correct for this account. Un-check "Log on using Secure Password Authentication" (unless specified otherwise by your email provider)

How do I change my SMTP server port in outlook? ›

How to amend your SMTP port in Outlook Express
  1. Open Microsoft Outlook Express then select Tools » Accounts.
  2. Select the Mail tab in the top navigation and highlight the account you want to change the outgoing port for. ...
  3. Now select the 'Advanced Tab' and change the Out-Going Server Port to 587 then click 'OK'

How do you fix 550 this message was classified as spam and may not be delivered? ›

Solution #1 – Enable SMTP Authentication in Outlook

If you are using the Microsoft Outlook email client, not having SMTP Authentication will cause several points to be added to the spam score. This can cause emails that otherwise would be allowed through to be classified as spam.

How do I fix relaying denied? ›

Dealing with “Relaying Denied”

Double-check your own email program's configuration — specifically its SMTP settings — making sure you're following your ISP's instructions. Double-check the email address you're sending to, making sure that it's correct. Try again later.

How do I fix sender not authorized for Relay? ›

It's likely that the email server isn't correctly set up to receive and relay messages from your organization. To fix this issue, forward this non-delivery report (NDR) to your email admin.

What does relay denied mean? ›

"Relaying" is when you send email to one mail server, expecting it to pass the email on to its intended recipient who resides on a different mail server (known as "non-local email"). A mail server will produce a "Relaying Denied" error when an unauthorized user attempts to send non-local email.

What is a 550 error? ›

Server error "550 this domain is not hosted here" indicates that the recipient address is not found or is inaccessible. Server error 550 or 550 Blocked Error indicates that the recipient is blocking your email on the recipient's email server.

What ports does SMTP use? ›

Which port should you use for SMTP? Ports 25, 465, 587, or 2525 for SMTP have all been considered standard SMTP ports at some point, but only 587 or 2525 really should be considered for modern use.

How do I fix 550 relay not permitted? ›

How to fix '550 Relay not permitted' in Mozilla Thunderbird on Windows:
  1. Launch your mail client.
  2. Under 'Tools' select 'Account Settings'.
  3. Scroll down your accounts and select 'Outgoing Server (SMTP)'.
  4. Select your outgoing server and click 'Edit'.
  5. Enable the 'Use name and password' option.

What is server Error 550 on Outlook Express? ›

550 Blocked error or 550 Requested action not taken: mailbox unavailable is an SMTP (Simple Mail Transfer Protocol) error code. Put simply, this message means that the email you sent was blocked by the recipient's email hosting server, and returned to you.

Why does my email not allow relaying? ›

Usually, you see this message when there is a conflict or inadequate information for the email account. The problem is almost always due to issues with your outgoing mail server settings.

How do you fix this error message 550 5.1 1 User unknown? ›

If the recipient doesn't have the email address that you're sending to, it will bounce the mail with the error message '550 5.1. 1 User unknown'. Solution: Always validate the recipient email address you've given in the email for any spelling mistakes or errors.

How do you fix 550 5.1 1 The email account that you tried to reach does not exist? ›

Solution 1: Confirm the recipient's email address

It sounds too simple, but the wrong email address is the most common issue that causes 5.1. x errors. Check for correct spelling and send the message again if you find an error in the email address. To resend the message in Outlook, see Resend an email message.

How do you fix 550 this message was classified as spam and may not be delivered? ›

Solution #1 – Enable SMTP Authentication in Outlook

If you are using the Microsoft Outlook email client, not having SMTP Authentication will cause several points to be added to the spam score. This can cause emails that otherwise would be allowed through to be classified as spam.

How do I find the SMTP server for my email? ›

You can generally find your SMTP email server address in the account or settings section of your mail client. When you send an email, with SMTP host Gmail or AOL, the SMTP server processes your email, decides which server to send the message to, and relays the message to that server.

How do I find my SMTP server name and port? ›

In Outlook, click File. Then navigate to Account Settings > Account Settings. On the Email tab, double-click on the account you want to connect to HubSpot. Below Server Information, you can find your incoming mail server (IMAP) and outgoing mail server (SMTP) names.

Is port 587 TLS or SSL? ›

Port 587 is often used to encrypt SMTP messages using STARTTLS, which allows the email client to establish secure connections by requesting that the mail server upgrade the connection through TLS.

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