[Dovecot] Different LDAP filters for different protocols

[James Devine]

Is it possible to query LDAP differently for different protocols?  I am
using dovecot for both pop3/imap and lmtp deliveries and there are
different enable flags in ldap for them.  I tried wrapping user_filter
inside the protocols in the file dovecot-ldap.conf.ext as shown below but
this didn't seem to work.

protocol lmtp {
        user_filter =
(&(objectClass=posixAccount)(cn=%u)(active=1)(msmtp=1))
}

protocol imap {
        user_filter = (&(objectClass=posixAccount)(cn=%u)(active=1)(mpop=1))
}

protocol pop3 {
        user_filter = (&(objectClass=posixAccount)(cn=%u)(active=1)(mpop=1))
}