Spam/Remove copy from server when moved from Inbox behavior change in Catalina?

I’ve been using SpamSieve with Mail on my Mac, and reading mail on my iPhone and iPad for years successfully. Something changed when I updated my Mac to Catalina recently, and SpamSeive to 2.9.38. My main email account is a POP account, and has been for decades. I have decades of old emails stored on my Mac. I keep the last 6 months or so around on the email server hosting that email account, and I access those emails from my iPhone and iPad.

The goal is for SpamSieve to run on the Mac, remove spam items from the Inbox so I only see good (non-spam) emails on the iPhone and iPad. This basically has worked for years. But when I changed to Catalina, I only saw a few emails on the iPhone and iPad, not all the good emails. It feels like the ‘Remove copy from server after retrieving a message’ with ‘When moved from Inbox’ setting is working faster/better in Catalina? Meaning when SpamSieve moves all new messages to the SPAM folder so it can examine them, that Mail setting now really removes those messages from the server. SpamSieve does its work and puts the good messages back into the Mac’s Inbox. BUT that doesn’t restore those good emails to the server, so I can’t see them on the iPhone or iPad! If I turn off the ‘Remove copy from server…’ option, ALL emails are left on the server. Both the spam and the good emails. I get ALL of those emails on the iPhone/iPad, which is not what I want.

Did I miss something that changed in Mail and/or SpamSieve? Is there a different combination of settings that will do what I want? Basically, my setup would work if all the mail stayed on the Server until SpamSieve finished its work, and THEN all the emails that were left as spam (not moved back to the inbox) were deleted from the server. They should stay in the SPAM folder on my Mac so I could review them in case something accidentally was put there that needed to be trained as good.

Getting the messages identified as SPAM off the server is the goal, with the good emails left on the server. How can I do that? Some combination of settings? An AppleScript that could be run after the SpamSieve rule?
Any assistance would be appreciated.

David

The best way to do this is to use IMAP or Exchange rather than POP. POP is not designed to work with multiple devices, and Mail’s options for removing POP messages from the server have rarely worked consistently or as described. You’re very lucky if doing this via POP has worked reliably for you up until now.

That’s not how it works. SpamSieve looks at the message while it’s in the inbox and either tells Mail “Yes, it’s spam, apply the rule action” or “No, it’s not spam, move on to the next rule.” So enabling SpamSieve is equivalent to having a regular rule that moves message to another mailbox—it’s just that the rule is only applied to the messages that are spam. The good messages are not touched.

SpamSieve works the same as always. It’s quite possible that Mail’s POP handling changed in Catalina.

Hmm… I’m not a fan of IMAP, at least for my own setup. I don’t want to rely on the mail server to store my email history. I want to store them for the long term. I prefer the POP model.

In any case, if SpamSieve truly leaves new email in the Inbox, then I can work with that. Is there a way for the good email to be left as unread after SpamSieve moves the spam items out of the Inbox?

I’ll try some different settings.

IMAP vs. POP doesn’t have much to do with storing for the long term. You can move messages from IMAP mailboxes to local mailboxes just like you can with POP.

That should happen automatically. Like I said, SpamSieve doesn’t touch the good messages. It doesn’t mark spam messages as read, either, unless you add a rule action to do that.