[Dovecot] proxy host specified as fqdn in userdb

[Apostolos Papayanakis]

Abstract from http://wiki.dovecot.org/PasswordDatabase/ExtraFields/Proxy

>
> host=s: The destination server's *IP address*. This field is required. 
> Note that currently it's required to use an IP address since no DNS 
> resolving is done.
>
Hello Timo,
  Here goes one more item for the v2.0 wishlist:
  Will it become possible to do dovecot imap proxying based on a "host" 
userdb attribute that is an FQDN (instead of a numeric IP as it is now)?
  It would simplify things for large smtp clusters that already do LDAP 
mail routing, based on per user "mailHost" attribute containg mail 
server FQDNs (according to "IETF Internet Draft LDAP Schema for Intranet 
Mail Routing", http://www.sendmail.org/m4/laser.txt). It is 
kinda redundunt to keep an extra LDAP attribute for "host" that contains 
essentially the same information as "mailHost" attribute, but in numeric 
form.

   I know the proposed change is not that important for many people, so 
don't really bother unless it is trivial to implement.

apap