Dovecot
We use Dovecot for both local delivery and IMAP access to mailboxes.
LDAP Users
Dovecot checks against our LDAP directory for users before attempting mail delivery or permitting access to a mailbox.
Dovecot performs Bind authentications meaning it tests the credentials provided by the user against the LDAP directory, and does not perform the password validation itself.
We permit the following login mechanisms:
PLAIN
(Plaintext passwords, with security added by TLS/SSL)LOGIN
(Obsolete, but still used by Microsoft services)
When a user authenticates, we confirm the login with the LDAP directory and permit access, either to the SMTP server via Dovecot SASL or to IMAP via Dovecot authentication.
Administration
Dovecot mostly services itself, you can check the logs by looking for
dovecot.service
in the system journal.
You can perform a selection of administration tasks with the doveadm
tool,
which has a great manpage.
This includes things like testing LDAP lookups (doveadm user
), listing folders
in a user mailbox (doveadm mailbox
), or viewing Dovecot service status
(dovecot process status
).