Slowly but surely IPv4 63.141.225.90 kee ... / 2013-12-17

Slowly but surely IPv4 63.141.225.90 keeps trying authenticated smtp on one server. The connection is kept open and there is 4 minutes between each attempt, probably to avoid detection. Searching for the IPv4 address gives multiple sites listing it for smtp auth attempts.

And the server doesn't need username/password based smtp authentication anyway, so I disabled all the mechanisms. In sendmail.mc format:

TRUST_AUTH_MECH(`')dnl
define(`confAUTH_MECHANISMS', `')dnl