Securing your email domain with DMARC, DKIM and SPF

2015-03-20 00:00:00 +0000

Having a number of domains that were registered long time ago and even once used for sending any email typically results in tons of spam being not only sent to these addresses — which you can just filter and ignore — but also from them as they are used to build fake headers by the spam software. Here’s one method to deal with that. Fake From headers in spam email are a known and widespread problem. I have experienced this with that I registered back in 2001 and for a while used on a mail server for friends: it’s quite amazing to see rejected spam still arriving in 2015 for because of two emails Michał has posted back in 2001 to a mailing list from that address!

Fortunately, there are now methods that are quite effective in preventing this type of (rather minor) reputation damage: