Email and Spam

I hate spam. And so do the people I manage mailservers for.

The domains I control (chubb.wattle.id.au) get a lot of spam (about 20:1 cf legitimate email). Therefore I've recently instituted some fairly draconian filtering to try to get rid of it before I see it.

This may stop or delay some legitimate email.

Junk email sent to addresses in my domains will be reported to spamcop.net, and if they come from within Australia, to the ACCC. In addition, a formal complaint will be made to the ISP from which the email originates; this complaint quite often results in the offending account's termination.

To maximise your chances of your email getting through:

• Send from a properly configured mail server. One that compiles with all the RFCs, uses a proper HELO string (preferably one that can by looked up in DNS), and has forward and reverse DNS mappings that match.
  For example, if you send via mail.an.isp.com.au, then the HELO string should be mail.an.isp.com.au and, if looking that name up yields an IP address of 1.2.3.4, then looking up 4.3.2.1.in-addr.arpa should yield a PTR record for mail.an.isp.com.au (or some other address that when looked up yields an A record for 1.2.3.4).
• Send plain text. HTML email is biased towards spam in the spassassin rules; and microsoft word attachments are really bad. Please never send them.
• We use DNS-based blacklists extensively.
• And we run a sender check: if my mail server cannot deliver email to the from: address in an email then it will not accept the message.

The checks used are very similar to those described on www.sput.nl except that we do not accept emails wholly in Dutch.