Mailman mailing lists are experiencing issues with emails sent to some providers (such as GMail and Yahoo) ending up in user's Junk folders.

This follows a period of subscription spam targeting Mailman, leading to users on those (and possibly some other) platforms that received the resulting subscription notification or rejected sign-up emails to mark them as spam, downgrading our Mailman server's IP and domain reputation.

Measures have been put in place to prevent significant sign-up spam and other measures are being considered. Where possible we are monitoring the rating of the Mailman server by these providers, which should improve after the spam rate has remained below their threshold for a period of time.