Dovecot: IMAP, POP3, LMTP, SASL Auth & ManageSieve Server
docker run --name dovecot \
-p ... \
-v $PWD/dovecot.conf:/etc/dovecot/dovecot.conf:ro \
fphammerle/dovecot
http://www.postfix.org/SASL_README.html#server_sasl_enable
# dovecot.conf
auth_mechanisms = plain login
passdb {
# https://wiki.dovecot.org/AuthDatabase/PasswdFile
# doveadm pw -s BLF-CRYPT -u user -p password
driver = passwd-file
args = username_format=%n /etc/dovecot/passwd
}
service auth {
# https://wiki.dovecot.org/Services#inet_listeners
inet_listener auth {
address = *
port = 12345
}
}
# postfix main.cf
smtpd_sasl_auth_enable = yes
smtpd_tls_auth_only = yes
smtpd_sasl_type = dovecot
smtpd_sasl_path = inet:dovecot:12345
smtpd_relay_restrictions = [...], permit_sasl_authenticated, reject_unauth_destination