SMTP Authentication Error

Question

Hi Y'all,

I am trying to setup a Mastodon server and I have it working however the email part is not working. My Email is done through a 365 Tenate and I have an smtp account. When I try to authenticate to send SMTP messages I get the following error "Net::SMTPAuthenticationError: 504 5.7.4 Unrecognized authentication type [CH0PR07CA0007.namprd07.prod.outlook.com 2023-05-05T12:46:17.326Z 08DB4D0A93F694B2]".

Upon doing some basic research it would seem to be related to a TLS mismatch however I believe my SMTP configuration is not adequate enough to fix this. My system is running Ubuntu 20.04.06 Server.

Here is my current SMTP configuration:
SMTP_SERVER=smtp-legacy.office365.com

SMTP_PORT=587

SMTP_LOGIN=******@domain.net

SMTP_PASSWORD=

#SMTP_AUTH_METHOD=plain

#SMTP_OPENSSL_VERIFY_MODE=none

#SMTP_ENABLE_STARTTLS=auto

SMTP_FROM_ADDRESS=******@domain.net

Any help is appreciated.

Answer 1

It looks like the issue might be related to the authentication method used by your SMTP server. The error message indicates that the authentication type is unrecognized.

To resolve this issue, you may want to try using a different authentication method, such as "login" or "plain". Uncomment the SMTP_AUTH_METHOD=plain line in your configuration file and see if that helps.

Additionally, you may want to enable STARTTLS encryption to secure your email communication. Uncomment the SMTP_ENABLE_STARTTLS=auto line in your configuration file to enable STARTTLS.

Here is what your updated configuration file might look like:

makefileCopy code
SMTP_SERVER=smtp-legacy.office365.com
SMTP_PORT=587
SMTP_LOGIN=******@domain.net
SMTP_PASSWORD=
SMTP_AUTH_METHOD=plain
SMTP_OPENSSL_VERIFY_MODE=none
SMTP_ENABLE_STARTTLS=auto
SMTP_FROM_ADDRESS=******@domain.net

Save the changes and restart your Mastodon server. Test your SMTP connection again and see if it works. If you still have issues, you may want to contact your email provider to check if there are any specific requirements or restrictions for SMTP authentication.

Answer 2

 

Hi @ AidenTheBotLol,

Just wanted to confirm if your local server has TLS1.2 enabled?

SMTP clients will need to use TLS 1.2 to connect to Exchange and send email. It is recommended that you enable TLS 1.2 and disable 1.0 and 1.1.

For more information ,please refer to this link:Exchange Online to Introduce Legacy SMTP Endpoint in 2022 - Office 365 for IT Pros (office365itpros.com)

(Note:Microsoft provides third-party contact information to help you find additional information about this topic. This contact information may change without notice. Microsoft does not guarantee the accuracy of third-party contact information.)

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