I have an account on an SMTP server. The server has a storage quota. I'd like the delete stuff from the server but keep it locally in case I need it. Just in case.

I'd like to be able to access the mail somehow on other computers and hopefully mobile devices on my network so that it can be searched when needed. I'm not sure what the best interface for that would be. A webmail client?

One option would be to use Thunderbird or another client to download the mail once in a while but disable deleting local messages when they are removed from the server. Would Thunderbird store the messages in a format I can use readily with other applications? Or should I use something else to download the mail?

What about situations where messages are moved from one folder to another on the server? Would I get a duplicate locally of the message appearing in both locations? Not sure how the storage and metadata actually are.

Also, is it possible in such a situation to put a message back on the server if I realize it was deleted in error?

Any idea would be welcome. I am a bit stuck.

I can use the command line comfortably but ideally I'd have a solution that doesn't rely on the terminal to find find messages and such. I don't really like terminal mail clients.