Reading Time: < 1minute
I've recently noticed one of the qmail SMTP servers I adminster had plenty of logged spammer emails originating from yahoo.com.tw destined to reache some random looking like emails (probably unexisting) again to *@yahoo.com.tw
The spam that is tried by the spammer is probably a bounce spam, since it seems there is no web-form or anything wrong with the qmail server that might be causing the spam troubles.
As a result some of the emails from the well configured qmail (holding SPF checks), having a correct existing MX, PTR record and even having configured Domain Keys (DKIM) started being marked, whether emails are sent to *@yahoo.com legit emails.
To deal with the shits, since we don't have any Taiwanese (tw) clients, I dediced to completely prohibit any emails destined to be sent via the mail server to *@yahoo.com.tw. This is done via /var/qmail/control/badmailto qmail control variable;
Here is content of /var/qmail/control/badmailto after banning outgoing emails to yahoo.com.tw;;;
qmail:~# cat /var/qmail/control/badmailto
The first 4 lines are default rules, which are solving a lot of badmailto common sent emails. Thanks God after a qmail restart:
qmail:~# qmailct restart
Checking in /var/log/qmail-sent/current, there are no more outgoing *@yahoo.com.tw destined emails. Problem solved …
More helpful Articles
Tags: Auto, bounce, cat, checks, com, common, configured, control, control variable, default rules, dkim, domain, Draft, god, legit, mail, mail server, mx, outgoing emails, plenty, ptr, Qmail, qmailct, reache, Result, shits, smtp servers, spam, spammer, SPF, twThe, var, well, Yahoo, yahoo com tw