Ok, interesting. I checked the docs of offlineimap (thanks, I hadn't found that one when googling!) and it looks like I could use the `maxage` option for the incremental option (I think I want to create a folder for each week, back it up , and delete it after a while).

Do you have anything set up with evolution to handle things automatically?

Sorry, my laptop where I had evolution got a new OS installed and I haven't configured it yet and just started mutt, but my original setup had a local archive folder, with sub-folders per year (I think, I even had a higher level grouping of 5 or 10 years). Unfortunately, I don't have setup right now to check, but I think it was semi-manual, like Evolution was archiving to a local folder automatically, then every new year I just moved the mails from the previous year into a folder).

Re offlineimap, just looked into isync/mbsync suggested here by others, it seems better from the description, I'm probably going to try it when I have some time: https://people.kernel.org/mcgrof/replacing-offlineimap-with-...