If you have a mixed MDaemon+Gmail environment where Gmail retrieves mail from MDaemon via POP3 (a reverse Multi-POP), at some point in the past 24 hours you may have noticed Gmail stopped accessing mail.
It appears that Gmail has changed how their Always use a secure connection (SSL) when retrieving mail feature works, and they now require a certificate signed by an authority that they trust, they no longer accept self-signed certificates.
This is a good and bad, self-signed certificates offer little or no security against man-in-the-middle attacks, and so can lead to a false sense of security, however, it’s annoying that this breaks your working configuration.
Between this and the recent announcement that Gmail will be dropping ActiveSync support for new accounts, it might be a good time to consolidate all of your users on a locally hosted and managed MDaemon server rather than relying on the moving support target of cloud hosting.
If you don’t already have a valid certificate, I previously wrote an article on where you can get Cheap SSL Certificates (I have no affiliation, and I receive no compensation for this referral. I also have not verified that their certificates pass Gmail’s tests at this time or in the future).