[Dovecot] Blocking certain hostnames/clients

[Steffen Kaiser]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Sun, 27 Oct 2013, Charles Marcus wrote:

> As a result of learning of the new 'Intro' App introduced by LinkedIn, and 
> discussing how to block SMTP access to my postfix server from these clients, 
> I'm now interested in doing the same for dovecot.

Reading the description, I would say: No valid user would AUTH into your 
IMAP server, so block those LinkedIn-IP addresses for all ports, but plain 
old 25. No need to fiddle in Dovecot and you'll save resources.

If you want to log them as incidents, you might look into:

# Most (but not all) settings can be overridden by different protocols 
and/or
# source/destination IPs by placing the settings inside sections, for 
example:
# protocol imap { }, local 127.0.0.1 { }, remote 10.0.0.0/8 { }

put a user-deny passdb {} in a remote { } block at the 1st place. However, 
I don't know if this works, though.

> The boss has expressed the desire to NOT block all email from them, just 
> disallow any of their clients from AUTH'ing (either SMTP or IMAP/POP).

would work, if you block all ports, but 25, from these IPs.

> I'd be interested if anyone has any kind of database of hostnames/IP blocks 
> of the freemailers out there that support adding 3rd party accounts, 
> especially ones supporting IMAP.

This does not read like a freemail, but just a gateway.

- -- 
Steffen Kaiser
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)

iQEVAwUBUm5r313r2wJMiz2NAQLUJwf+LWQVx4rJrcrmspDT4K1BnZTKIV7mS62e
2L/3TwYSGic6SzAUbQR25DYZDOaBnsOdlk2MND1fRq8mRNXTjPKGiGUHRQ5qC+qA
WE3+zixXObD2/YFiH8NjAXy3waURhoYXkGdfNbiMfJoaVpwi2KtSQTWFD5WtEyvm
TuyQP0UFpRiM87c9g6M634/lNiUKUK3m65s02dkJxcfEf7SQVpRESjKOtyys2hm3
gx9hgphWsZpaBYGhzs9q7nydy2WyYgLvreBtugid5YhHmTGB2YkUnNqe57jt0iAM
C/CioVSZkJrTJ40ja4BO1iYifkxHmdo2ar88w4adnzWUsMEInQZrDQ==
=lLXQ
-----END PGP SIGNATURE-----