Resolved disable plaintext (PLAIN) authentication in imap/dovecot and smtp/postfix breaking webmail/roundcube

[Wolfgang Reidlinger]

Hi there,

After following this article to disable plaintext authentication for my mail service (imap/dovecot and smtp/postfix) I ran into the following issues with Roundcude webmail service.
https://support.plesk.com/hc/en-us/articles/213400829

Roundcude webmail is not working, showing me SMTP Error (535): Authentication failed. Also in the logs I can see that PLAIN is stilled used.

2022-04-19 14:33:07 postfix/smtpd[3667] disconnect from localhost[::1] ehlo=1 auth=0/1 quit=1 commands=2/3
2022-04-19 14:33:07 postfix/smtpd[3667] warning: localhost[::1]: SASL PLAIN authentication failed: no mechanism available
2022-04-19 14:33:07 postfix/smtpd[3667] warning: SASL authentication failure: Couldn't find mech PLAIN
2022-04-19 14:33:07 postfix/smtpd[3667] TLS SNI localhost from localhost[::1] not matched, using default chain
2022-04-19 14:33:07 postfix/smtpd[3667] connect from localhost[::1]

To me it seams that some configuration step is missing. Testing the setup/config with thunderbird email client everything is working and the logs show correct behaviour.

2022-04-19 15:34:59 dovecot imap-login: Login: user=<***@domain.com>, method=CRAM-MD5, rip=*************, lip=********, mpid=17871, TLS, session=<OjN78QHdBldTr1fk>

Reading the comments of the first article, finding out that the link is not working.

Maximilian Hermann April 15, 2020 18:07
I think it is a good way to do this, but you have to change Roundcube Settings as well otherwise SMTP won't work anymore, because roundcube seems to be using plain by default: https://support.plesk.com/hc/en-us/...ication-via-Roundcube-AUTHENTICATE-DIGEST-MD5

Than I found this article telling me to revert the changes from the first artikle.
https://support.plesk.com/hc/en-us/...esk-server-encryption-needed-to-use-mechanism

I mainly use email client but I also want that this webmail service is working.
Anybody got this roundcube webmail service to use secure authentication without breaking the service?


OS: Ubuntu 20.04.4 LTS
Product: Plesk Obsidian 18.0.43 Update #1, last updated on April 18, 2022 10:59 AM

 

[Kaspar]

Edit file /usr/share/psa-roundcube/config/config.inc.php and add the following configuration:

$config['smtp_auth_type'] = 'CRAM-MD5';
$config['imap_auth_type'] = 'CRAM-MD5';

 

[Wolfgang Reidlinger]

Edit file /usr/share/psa-roundcube/config/config.inc.php and add the following configuration:

$config['smtp_auth_type'] = 'CRAM-MD5';
$config['imap_auth_type'] = 'CRAM-MD5';

@Rasp thanks you saved my day! It's working now.

2022-04-19 17:17:38 dovecot imap-login: Login: user=<[email protected]>, method=CRAM-MD5, rip=::1, lip=::1, mpid=12666, TLS, session=<1FCaYAPAAAAAB>