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I have to use a Win2k/Exchange 2k setup for our companies mail. There is no way to change or upgrade that. Due to various hacking & spam scenarios that played out, we implemented a linux based relay using qmail & perdition. That seemed to quell our primary issues however, now, a sender does not receive a bounceback when mail is sent to a non-existent user in our organization. I am certainly open to other (FOSS only) solutions but, am stumped so far. Here are our requirements:

  • must have POP & SMTP access from the outside world using authenticated lookup
  • must be mail relay in every since. In stays in, out goes out. No anonymous mailings.
  • must integrate with 1 or more spam/rbl lists/groups for filtering

Ideally, I would just like to enable some type of AD LDAP or pop lookup on the same box so that when a user is not found it would bounce the msg back to the originator. I am having a difficult time finding a way to do this. I've thought of just performing a user dump for it to check against but, that can be cumbersome to keep updated everytime someone leaves the company. The current scenario performs a user lookup & if it doesn't find the user it just drops it.

Any suggestions ? Might there be another way to configure this better ? Maybe a different package would work better ?

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I'm a bit confused. Are you saying that qmail isn't configured to do LDAP lookups now, or that it is, but that it's not bouncing messages with failed lookups? – Evan Anderson Jun 3 '09 at 17:51
it is performing a pop before smtp scenario. So, technically it's not a LDAP lookup just a pop user lookup. – Pete Jun 3 '09 at 18:31
up vote 1 down vote accepted

You've already been given a solution to create static tables for control. Another solution woulde be to use qmail-verify.

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I have the same requirements. I have a cronjob that does and ldap search against active directory looking for valid mail users, and then writes a file that is used by postfix.

The relevant magic is

ldapsearch -h -LLL -D '' -y ~/.ad-password -x -Z -b 'dc=contoso,dc=com' '(msExchRecipientTypeDetails=1)' mailNickname > /tmp/$$.exchange

From there you'll have to rewrite the output to match whatever you need for qmail. For postfix I write a table that is then run through postmap.

I have the script do a diff and e-mail me the diff results so I can tell if it's going crazy.

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