create rule that automatically flags certain messages

I have this question too. Was it answered somewhere else?
Thanks,
Nick

Thanks for this workaround Benny.
It would answer the query fine, except that I am finding that whatever the combination of $MailFlagBit0/1/2 keywords I set, I always end up with a red flag when I clear and reapply the rule.

Hmm, maybe this is a visual issue which clears up if reselecting the
mailbox?

You can enable the “Raw Flags” column in the message list to see a
list of the current IMAP keywords for the message.

Further experiment has yielded some more info.

Different combinations of flags do produce all 7 flag colours, according to the following pattern:

Bit0 = orange (there only needs to be one Bit0 keyword, though 0+0+0… will still produce orange)
Bit1 = yellow (ditto)
Bit2 = blue (ditto)
Bit0 + Bit1 = green (any combination: 01, 10, 101…)
Bit0 + Bit2 = purple (ditto)
Bit1 + Bit2 = grey (ditto)
Bit0 + Bit1 + Bit2 = red (ditto)
The order of the keywords does not matter, and the \Flagged keyword has to be present.

Flagging via the Message menu or CMM does not add any (visible) keywords except \Flagged, so flags can be changed or removed at will. When flagging via rules with keywords however, the existing flags are not removed, so if one rule flags a message (say) orange and a later rule tries to flag it blue, there will now be both Bit0 and Bit2 keywords, so the result will be purple. The workaround is to precede the keyword actions with three actions to remove existing keywords (whether or not they exist).

(Question: is this the only GUI for removing these keywords?)

Manual flagging via menu over-rides any flags applied by other means (though it does not remove the visible keywords). It may be that keywords are still applied internally, but do not appear in the Raw Flags column, and there is some internal routine for wiping the slate each time a new flag is applied.

(Incidentally Benny, it says Upload Quota Reached below. Does this mean that we cannot upload screenshots?)

You don't need three preceding actions to clear the bits. Just set/unset all three bits, that is, you always need 4 actions (\Flagged and 3 bits). Sorry about not being clear about that. I forgot the details.

GUI: The bit-flags are not cleared when removing flagged, but this could be an option I guess.

Quota Reached:: Yes. When I clean up, it fills up so quickly that it's hardly worth the effort. Use “Help > Send Feedback” in MailMate to send me screenshots if needed.

Note: I believe it's possible to create 7 template rules (without conditions) named “Flag Yellow” etc. Then these can be dragged holding down option (to copy) to use them repeatedly (you would need some dummy smart mailbox to store them). A rule can have children which means you can then make a rule with conditions only and then drag the color-action to add it as a child to the condition. I'm not sure you'll find this easier, but now you know :-)

Thanks Benny, that's a much neater solution for setting the bits. (You can tell that this is new territory for me.)
I'll send you an email with some other flag-related stuff, as suggested.
Nick