Postfix / Thunderbird / Cyrus SASL2: Username Or Password Invalid

Question

I'm quite certain that I've entered my password correctly; that Thunderbird regards it as incorrect is I expect due to a Postfix or Cyrus SASL misconfiguration.

I am perpetually confused about eMail server configuration. That I want to host my own mail is out of a desire to stop paying others to host it, as I have lots of mail usernames.

I've got Postfix, Dovecot and Cyrus SASL2 installed on my server. Dovecot works for Thunderbird's POP3 client; I want to now set up both Dovecot's IMAP client and Postfix's outgoing STMPD server.

Thunderbird's config:

Incoming: IMAP
Hostname: image.example.com
Port:     143
SSL:      STARTTLS
Auth:     Normal Password

Outgoing: SMTP
Hostname: smtp.example.com
Port:     25
SSL:      STARTTLS
Auth:     Normal Password

Note that Thunderbird regards the above settings as correct; I only have trouble with my password.

# /etc/postfix/main.cf
smtpd_sasl_path = smtpd
smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
broken_sasl_auth_clients = yes
# smtp_recipient_restrictions = permit_sasl_authenticated, permit_mynetworks
smtpd_client_restrictions = permit_sasl_authenticated
smtpd_recipient_restrictions = permit_sasl_authenticated, reject_unauth_destination

# ls -l /etc/sasldb2
-rw-r----- 1 root root 12288 Jan  2 12:41 /etc/sasldb2

/etc/dovecot/conf.d/10-auth.conf makes no mention of SASL.

Answer 1

This seems like a typical confusion that Dovecot would need Cyrus SASL.

Many people confuse SASL with one specific SASL implementation: the Cyrus SASL library. Dovecot has its own SASL implementation which may at some point be separated from Dovecot itself to "compete" against Cyrus SASL library in server side.

Postfix can use Dovecot as its SASL provider as explained in Postfix and Dovecot SASL HowTo. It's recommended to use submission on port 587 instead of SMTP port 25, as port 25 is usually blocked on consumer grade connections, and this also enables using different settings for authenticated users. Therefore, the configuration files necessary are /etc/postfix/master.cf and /etc/dovecot/conf.d/10-master.conf.