[horde] spammers targeting horde/imp as spamming tool

[D G Teed]

Hey,

Has anyone read this thread:

http://www.nabble.com/Spamming-using-imp--td15431034.html

Spammers are using brute force or phished login information to gain
access to imp, and then sent out spam

I've received a spam complaint which seems to echo this situtation.

The first tool which comes to my mind is DenyHosts.

Any other comments or thoughts on this trend?

--Donald