search for: checksom

..., so both servers can figure out together the new UIDs. I haven't thought this through yet. - Conflict resolution for message flags/keywords. The protocol would normally send flag changes incrementally, such as "add flag1, remove flag2". Besides that there could be a 8bit checksom of all the resulting flags/keywords. If the checksum doesn't match, request all the current flags. It would be of course possible to send the current flags always instead of incremental updates, but this would waste space when there are lots of keywords, and multi-master replication...