A user defined spam filter would really distinguish this app from gmail. Surely this wouldn't be so hard?
If you're accessing your email using IMAP, wouldn't it just be easier to use the spam filter from your server, if it has one that is? I have three email accounts Google, Yahoo, and Outlook and just use their spam filters and see very few spam messages in any of my inboxes. Of course I sync the spam folders as well so I can check them for any messages placed in there by mistake.
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