This documentation is for Dovecot v2.x, see wiki1 for v1.x documentation.

Restricting Access

Restricting IMAP access

If you want to give POP3 access to everyone, but IMAP access only for some people, you have to use passdb which allows selecting this.


Set PAM service name to *, ie.:

passdb pam {
  args = *

That way PAM uses /etc/pam.d/imap for IMAP, and /etc/pam.d/pop3 for POP3.

In /etc/pam.d/imap you could then use eg. the module:

# allow IMAP access only for users in /etc/imapusers file
auth    required item=user sense=allow file=/etc/imapusers onerr=fail 


You can use the %Ls variable which expands to imap or pop3 in password_query, eg:

password_query = SELECT password FROM users WHERE userid = '%u' and (imap_allowed = true or '%Ls' = 'pop3') 


Just like with SQL, you can use %Ls in pass_filter, eg.:

pass_filter = (&(objectClass=posixAccount)(uid=%u)(service=%Ls)) 

That would require setting both service=pop3 and service=imap attributes to the user objects.


You can create a deny passwd-file based on the service:

passdb passwd-file {
  args = /etc/dovecot/deny.%Ls
  deny = yes

This makes Dovecot look for /etc/dovecot/deny.imap and /etc/dovecot/deny.pop3 files. If the user exists in it, the access is denied. The files don't need to have anything else than one username per line.

Note that this deny passdb must be before other passdbs. It also means that it can be used with any other passdb, not just with passwd-file passdbs.

Restricting IP Access

It's possible to allow a user to authenticate only from a specific IP or network. This is especially useful for master users. This can be done by returning [wiki:PasswordDatabase/ExtraFields/AllowNets allow_nets] extra field in passdb.