Opera not marking spam messages

I have a spam IMAP folder, and it is populated by OSX Mail.app and Opera for Windows. There are some messages in that folder that Opera does not think are spam: Mail.app obviously put them there. But I would like to train Opera to regard them as spam, and I mark them as spam, but they do not stay marked: they are immediately unmarked as spam in Opera, although they remain in the folder.

I can't figure out why Opera would unmark these messages. Any clues? Any hints as to what I could do to fix the problem?

Welcome to the My Opera community!

On the IMAP tab in the account's properties, is the spam folder setting set to the IMAP spam folder in question?

Originally posted by hteasley:

I can't figure out why Opera would unmark these messages. Any clues?

Mail.app probably adds an IMAP keyword to spam messages. It might not be the same one that Opera uses. If so, Opera might drop the keyword if it doesn't support it for spam use. Not sure. Thunderbird looks for messages that have an IMAP keyword that matches the substring "junk" and "notjunk" for example. Never checked what Opera does. (Will have to do that.)

I can't test since I don't have OSX. But, you can log the connection and see what spam keywords Mail.app puts on those messages and what Opera does with them.

Originally posted by hteasley:

But I would like to train Opera

On the IMAP tab in the account's properties, if you don't have "disable local spam filter" checked, Opera's spam filter will be enabled for messages for the account. Right-click on "All Messages/Spam" and goto properties. You'll see there's an internal filter that detects common spam.

Also, on the options tab, there's a "learn from labeled messages" that's enabled. What this does is learn from messages you mark as spam and learn from false positives that you unmark as not spam. This can work very well, but it requires lots of training. After marking a few messages as spam, at first, *a lot* of your legit mail will be tagged as spam too. You'll then have to mark any legit mail you find as "not spam" so Opera learns. Eventually though, it will work pretty well. Note that unchecking "learn from labeled messages" should clear what Opera has learned. So, if you need to reset it, uncheck it, close out the dialog, go back in and check it.

But, if your IMAP server has server-side filtering and it's good, you should just rely on that and disable Opera's spam filter for the account.

Also, you can add your own explicit rules in the spam filters properties if you want.

Also note that if you don't want to show spam in regular views, click the view button on the mail toolbar above the message list, goto "show" and uncheck "show spam".