Similarly, I configured my mail server to use the system "tag.user@domain". So you can't use the same heuristic as gmail, because if you try to do an untagged e

Similarly, I configured my mail server to use the system "tag.user@domain". So you can't use the same heuristic as gmail, because if you try to do an untagged email, you likely just give the tag, which doesn't correspond to a user.