DISCOURSE_SMTP_AUTHENTICATION no documentation? None not working

AI-generated summary

The discussion revolves around the DISCOURSE_SMTP_AUTHENTICATION setting in Discourse. inquiry is trying to set it to none to avoid providing a username and password to SMTP, but is encountering an error message that says Invalid authentication method. Must be plain, login, or cram_md5. Despite trying discourse-doctor and rebuilding, the issue persists. inquiry has tested their mailer outside of Discourse and it works fine. Another user, inquiry, suggests commenting out the DISCOURSE_SMTP_USER_NAME and DISCOURSE_SMTP_PASSWORD lines in containers/app.yml to fix the issue, as seen in this post. The goal is to use bokysan/docker-postfix without requiring login credentials.

I’ve read on the form that I can set DISCOURSE_SMTP_AUTHENTICATION to none so a username and password wouldn’t be provided to smtp.

DISCOURSE_SMTP_AUTHENTICATION: none

However when I set it as none and try discourse-doctor I get:

======================================== ERROR ========================================
                                    UNEXPECTED ERROR

Invalid authentication method. Must be plain, login, or cram_md5.

====================================== SOLUTION =======================================
This is not a common error. No recommended solution exists!

Please report the exact error message above to https://meta.discourse.org/
(And a solution, if you find one!)

When I try to login I get:

postfix-email-server-1  | 2025-04-25T05:48:22.788077+00:00 INFO    postfix/smtpd[3330]: connect from unknown[172.17.0.1]
postfix-email-server-1  | 2025-04-25T05:48:22.794598+00:00 INFO    postfix/smtpd[3330]: lost connection after AUTH from unknown[172.17.0.1]
postfix-email-server-1  | 2025-04-25T05:48:22.794735+00:00 INFO    postfix/smtpd[3330]: disconnect from unknown[172.17.0.1] ehlo=2 starttls=1 auth=0/1 commands=3/4
postfix-email-server-1  | 2025-04-25T06:00:09.568494+00:00 INFO    postfix/smtpd[3340]: connect from unknown[172.17.0.1]
postfix-email-server-1  | 2025-04-25T06:00:09.576873+00:00 INFO    postfix/smtpd[3340]: lost connection after AUTH from unknown[172.17.0.1]
postfix-email-server-1  | 2025-04-25T06:00:09.576989+00:00 INFO    postfix/smtpd[3340]: disconnect from unknown[172.17.0.1] ehlo=2 starttls=1 auth=0/1 commands=3/4
postfix-email-server-1  | 2025-04-25T06:06:44.547155+00:00 INFO    postfix/smtpd[3330]: connect from unknown[172.17.0.1]
postfix-email-server-1  | 2025-04-25T06:06:44.561004+00:00 INFO    postfix/smtpd[3330]: lost connection after AUTH from unknown[172.17.0.1]
postfix-email-server-1  | 2025-04-25T06:06:44.561158+00:00 INFO    postfix/smtpd[3330]: disconnect from unknown[172.17.0.1] ehlo=2 starttls=1 auth=0/1 commands=3/4
postfix-email-server-1  | 2025-04-25T06:07:20.702285+00:00 INFO    postfix/smtpd[3340]: connect from unknown[172.17.0.1]
postfix-email-server-1  | 2025-04-25T06:07:20.712755+00:00 INFO    postfix/smtpd[3340]: lost connection after AUTH from unknown[172.17.0.1]
postfix-email-server-1  | 2025-04-25T06:07:20.712960+00:00 INFO    postfix/smtpd[3340]: disconnect from unknown[172.17.0.1] ehlo=2 starttls=1 auth=0/1 commands=3/4
postfix-email-server-1  | 2025-04-25T06:07:57.695045+00:00 INFO    rsyslogd: -- MARK --

Destroy and rebuild didn’t help.

I’ve tested my mailer outside Discourse and it’s working fine. I’m using bokysan/docker-postfix which doesn’t require login and I’m happy with it.

I’m aware of another related post but the none option seemed to be a valid option there:

I’ve fixed it by commenting the following lines in containers/app.yml

    #DISCOURSE_SMTP_USER_NAME: user@example.com
    #DISCOURSE_SMTP_PASSWORD: pa$$word