[feature suggestion] Optional copy-only instead of archive

[jfabini]

I'm accessing my (large) IMAP account from several clients, for convenience and redundancy matters.
Archiving older emails on one of these client devices (say, client X) to local folders removes them from the IMAP server. As main consequence only IMAP client X can access all emails (including the archived ones) but all other clients have an incomplete view. This is no viable solution for me.

A "copy" option instead of "archive" (potentially as a check-box: "leave messages on server") could solve this issue: All client devices but X can be configured to copy old emails to local archive folders (e.g., messages older than 365 days). Finally, client X - the last one to run - does an archive that deletes the copied messages.

Obviously this complicates the archiving process substantially, as the archiving add-on must keep track of already archived messages to skip potential duplicates on copy: the archive add-on may be run a second time on a specific client A and find emails that have been copied already (to local folders on client A) but not deleted by the archive process that is run by client X only. So the downside of this feature is a kind of mandatory statefulness that likely may result in increased complexity, slower operation and an increased likelihood of unexpected cases. However, it's feasible - the Awesome AutoArchive TB add-on included all the needed functionality and did a great job but unfortunately is no longer maintained/updated (incompatible with TB 60/63+).

Thanks in advance for considering this feature request

[Brummolix]

Right now the addon uses the built in archive functionality. It collects all messages that shoud be archived and tell Thunderbird to do so (just as you would manually mark all mails and call the context menu in Thunderbird).
I can understand that you want to have such a copy feature. But as you already described it would be more complex.
Probably this would be a major rewrite of the whole add-on.

Therefore I don't think I will do it at the moment.