The other day I was thinking it would be cool if you could detect
legitimate replies to mail I send.
Everyone gets spam with subjects like this:
Re: some type of trash subject
Obviously those are not replies to a message you sent.
That got me thinking of ways to authenticate a legitimate reply
We have run our servers with a decoy, our MX records have been like this
for 10+ years:
mx0.example.com
mx1.example.com
mx2.example.com
mx1 & mx2 are real servers. mx0 is nothing, it points to an IP address
that is controlled by us but there is no server.
The concept being that some spammers at
