[Dovecot] Dovecot LDA, LDAP, Postfix and Spawning programs..

Jorgen Lundman lundman at lundman.net
Thu Nov 16 00:42:54 UTC 2006

Qmail, when using LDAP, a user can specify delvieryProgramPath, or a .qmail 
file, to launch something like procmail. Qmail correctly setuid() to the uids 
set for the user in LDAP, as well as set up the common env vars (HOME, USER, 

We moved to Postfix but found that it is quite lacking in the features supported 
when it comes to "virtual" users. No .forward, and if you set up an alternate 
transport, they are run as "any user but root, nor postfix, nor the 
virtual-user's uid". And worse, does not even supply the HOME/MAILDIR values to 
transport delivery plugin. (Forcing it to getpwnam() or similar).

I have an option to make my own setuid program to query LDAP (postmap -q would 
work), setuid() and call, say, procmail.

It has been suggested I can use "maildrop" as it can talk to LDAP.
However, I picked "Dovecot" as my pop3/imap program due to an irrational dislike 
of Courier imap.

So, if I tried Dovecot-LDA, would it support the user optionally having a 
".forward" file, or perhaps the LDAP attribute deliveryProgramPath, or some 
other way to filter based on subject/body to sort, and/or forward, mail?

If it can use LDAP, will it setuid() to the users uid (as set in LDAP, assuming 
I cook the LDAP conf entries correctly) when delivering(I'd hope so!) and 
running external filters?

I am still running rc10, which works well but flips out regularly. (Previously 
mentioned 'too many files open' bug, some leaks in locks) I will upgrade when 
the LDAP changes are deemed stable.


Jorgen Lundman       | <lundman at lundman.net>
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