[CentOS] [OT] List of all email users

Bill Campbell centos at celestial.com
Fri Oct 31 19:49:25 UTC 2008

On Fri, Oct 31, 2008, Jussi Hirvi wrote:
>John R Pierce (pierce at hogranch.com) kirjoitteli (30.10.2008 17:39):
>> and what about the user accounts in /etc/passwd ?
>Hm, yes, never thought of that! That would be a very good (certainly easy)
>approach, though with its own limitations (it misses those users whose mail
>is forwarded in /etc/aliases to external addresses like gmail.com etc.).

I have a routine that pulls addresses from all the aliases files defined in
the postfix main.cf file, and gets all non-admin accounts from /etc/passwd,
combining the two to get all valid user names.  It then gets all the
domains from the postfix mydestination, combining the user names with these
domains to build a large virtual file for a border MX server that has no
users to allow it to validate incoming mail.

This have been working nicely for several years at an ISP with about 10,000
e-mail accounts.  The border MX server does preliminary IP based anti-spam
and uses amavisd and clamav to scan for phishing and worms that attack the
Microsoft virus, Windows, but does no spam checking.  It then sends
messages that pass amavisd to a cluster of servers that do spamassassin
checking, and delivery to NFS mounted Maildir stores.

INTERNET:   bill at celestial.com  Bill Campbell; Celestial Software LLC
URL: http://www.celestial.com/  PO Box 820; 6641 E. Mercer Way
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