Remote check for over-quota condition of the mailbox

Question

At least while migrating, and perhaps afterwards, our system utilizes a relay based on sendmail which trims a lot of spam based on simple rules (milter-greylist, milter-regex, banner delay, DNS RBL) and passes the rest to an internal system (some domais go to specific boxes and mostly to our old mail server, now the new Sun MS).
After implementing Sun JES infrastructure, LDAP in particular, we added LDAP routing to sendmail so that the relay knows which usernames exist - and this tremendously decreased bounce letters due to spam for inexistent recipients (now the error is returned within SMTP dialog of spammer to relay).
However I can imagine that when some users' boxes climb over quota and perhaps exceed grace time so their mails won't even be queued by Sun MS, we'll again have a flow of bounces from Sun MS to spam senders.
The question is: Is there some LDAP flag-attribute that is set for overquota boxes, so our relay can take that into account?
I think it is easily possible to craft one if it does not exist now (i.e. with a cron script), but perhaps I'd reinvent the wheel? (Again!?)

Answer 1

For reference, here are the tricks I used to configure the sendmail relay to know about
domains and users defined in Sun Messaging Server.
1) Since we custom-built sendmail, I had to define LDAP in site.config.m4 and rebuild, i.e.:
APPENDDEF(`confMAPDEF', `-DLDAPMAP')
APPENDDEF(`confLIBS', `-lldap')
APPENDDEF(`confINCDIRS', `-I/usr/local/include')
APPENDDEF(`confLIBDIRS', `-L/usr/local/lib')Stock binaries of many distributions have LDAP support built in already, this can be
checked by a command like:
# /usr/lib/sendmail -d0.1 -bv root | grep LDAP
Compiled with: DNSMAP LDAPMAP LOG MAP_REGEX MATCHGECOS MILTER MIME7TO8
                SASLv2 SCANF USERDB USE_LDAP_INIT XDEBUGWe don't need to extend the DSEE schema with the one supplied with sendmail,
Sun's Messaging Server schemas are adequate. We only need to point sendmail
query filters to the correct attributes.
2) In sendmail.mc I defined 3 lines, the connect spec to our LDAP server named
"dps" (can be quickly redefined via /etc/hosts), the LDAP routing search filter
(note: it's one very log line), and a ldaproute-domains file which lists names of
recipient domains which should be looked up in LDAP (one domain per line; it
does not need to be compiled by makemap):
dnl # See http://www.sendmail.org/m4/ldap_routing.html
dnl # mailuserstatus=overquota can be set by Sun Messaging store server
dnl # mailuserstatus=inactive, etc. may be set by DA admin
dnl # dps is the directory (proxy) server name
define(`confLDAP_DEFAULT_SPEC',`-h dps -b dc=domain,dc=com)dnl
FEATURE(`ldap_routing', `ldap -1 -T<TMPF> -v mailHost -k (&(objectClass=inetLocalMailRecipient)(|(mailuserstatus=active)(inetmailgroupstatus=active))(|(mail=%0)(mailLocalAddress=%0)(mailalternateaddress=%0)(mailequivalentaddress=%0)))', `ldap -1 -T<TMPF> -v mailRoutingAddress -k (&(objectClass=inetLocalMailRecipient)(|(mailuserstatus=active)(inetmailgroupstatus=active))(|(mail=%0)(mailLocalAddress=%0)(mailalternateaddress=%0)(mailequivalentaddress=%0)))', `bounce')dnl
LDAPROUTE_DOMAIN_FILE(`/etc/mail/ldaproute-domains')dnlRecipients' addresses (or aliases) should be defined in the attributes checked above,
have an objectClass=inetLocalMailRecipient and a mailuserstatus=active.
At least one of the attributes, mailHost (set by DA while provisioning users) and/or
mailRoutingAddress, should have a value in order to match the query.
See details on how sendmail interprets the query results in the docs: [http://www.sendmail.org/m4/ldap_routing.html]
Note/TODO: These rules don't check for inactive domains as a whole.
3) Of course, the config file template sendmail.mc must be compiled to actual
configuration file sendmail.cf, with our paths that would be this command:
# cd /usr/lib/sendmail-cf/m4 && m4 /etc/mail/config/sendmail.mc > /etc/mail/sendmail.cf4) Populate /etc/mail/ldaproute-domains with the domain name(s) already supported
by the LDAP server, one domain per line. Any other domains are subject to "old"
routing method(s) which was configured on the relay (i.e. mailertables, etc.):
# /etc/mail/ldaproute-domains
# This file lists domains which have actual usernames to receive messages.
# Catch-all domains are listed directly in mailertable.
domain.com
test.domain.com
hosteddomain.org
#willmigrateandupdate.anotherdomain.org5) Restart sendmail, watch the logs for a while, try to submit mails to existing and
inexistant users, to active and inactive ones, etc...
Enjoy the no-bounce world :)
Edited by: JimKlimov on Dec 5, 2008 8:23 PM
Updated ldap search with clauses for mail groups:
(|(mailuserstatus=active)(inetmailgroupstatus=active))