Email in local Spam folder (Apple Mail) is being delivered to POP clients

After updating to El Capitan from Yosemite, email that SpamSieve properly identifies as spam and moves to the local Spam folder on my Mac is now being delivered to POP clients on other computers. Previously, before updating from Yosemite any emails that were moved to the local Spam folder by SpamSieve were of course not delivered to any other email clients.

I made sure to update to the latest version of SS before upgrading to El Capitan. I rechecked the mail rule. It is correct. SS commands do appear in Apple Mail. And, like I said the spam messages are being moved to the Spam folder On My Mac as before.

I have 1&1 hosted email. Nothing has changed on their end.

Any help would be greatly appreciated. Thank you!

Jay

You are lucky that this ever worked for you. POP is simply not designed to be used in that way. If a Mac using POP sees a new message before the Mac with IMAP+SpamSieve, it will download the message to its inbox, and there is no mechanism for it to notice the message subsequently being removed from the IMAP inbox. I guess in that past you got lucky and the POP Mac happened to check for new mail at moments when the inbox was clean.

The solution is either to use IMAP (or Exchange) instead of POP on all the Macs, or to install SpamSieve on each of the POP Macs.

Yes, it worked before because I set up a dedicated old Mac running SpamSieve via IMAP on Apple Mail to check for email every minute. It pretty much caught everything.

After updating to El Capitan I use the same settings and SpamSieve moves the spam to the Spam folder. However spam messages that have been in the Spam folder for hours, even overnight, are being delivered to POP clients on other machines. This is new behavior since the update to El Capitan.

I know Apple Mail is different in El Capitan. Maybe the only way to get it working as before is to export the corpus and do a clean install of Yosemite and install SpamSieve on 10.10.5 Apple mail.

There are a lot of changes and new bugs in the El Capitan version of Mail. It’s possible that it has changed the way messages are expunged from the server.

Rather than exporting the corpus, you should just copy over the training data.

Another option is to use a Spam mailbox on the server. Moving a message from one server mailbox to another should happen immediately, whereas there is often a delay before messages are expunged when moved to a local mailbox.