I'm managing a bulk email service for the company I work at and a recent change to SpamAssassin has started flagging emails sent by our bulk-email solution with 'RAND_MKTG_HEADER'. I can't find much about this on the internet other than 'Has partially-randomized marketing/tracking header(s)'. The thing is, the software doesn't randomize any of the marketing headers for the campaigns sent with it, so I'm a bit confused as to the hows and whys and what I can do to fix this issue.
Naturally campaigns IDs are randomized UIDs, that's the nature of indentifying things uniquely. If anyone has any insight as to what this particular flag entails and what I can do to fix the issue it would be GREATLY appreciated as it's starting to impact our legitimate customers with delivery issues.
Thanks in advance!
It's likely caused by a custom X- header prefix, i.e. you have an X-something- prefix in your mailer software. If you happen to use Mailwizz, here is the solution: https://kb.mailwizz.com/articles/low-score-in-spamassassin-because-of-the-rand_mktg_header-rule/
You can essentially fix the problem by changing the custom header prefix to a traditional X- prefix.