In Outlook as well as in the IMAP MTA I use under Emacs, I have the ability to move emails to folders on other IMAP accounts/servers.
This is very helpful to for example move (rather than forward) an email same from my work account to say my personal email account (or vice-versa). Among other things, this keeps the email headers and body generally intact.
Currently, it seems like K9 only allows moving emails to folders under the same account.
I imagine it shouldn’t be hard to allow one to “navigate up a level” to access the folders of another account.
I believe that an intra-account message “move” only requires an IMAP server-side “rename” (and a redraw of the client-side message list display). On the other hand, an inter-account message move requires that the message be pulled to the client from the first account and then written to the second server/account. So, an inter-account message “move” is rather more complex and resource intensive, especially if the message is large and/or the client is on a slow network.
I’m not saying that this can’t/shouldn’t be an option for a mobile device client, just that someone invoking an inter-account message move needs to be warned of/understand the full implications - including the impact on metered data usage.
Good points and for that reason one may not want to transfer over thousands of messages at a time.
But often I get a personal message on my work account (or vice-versa) that I would like to transfer over and it’s a PITA to have wait until I get back to my PC to do it on another full-fledged MTA.
Also, with more and more people have unlimited or near unlimited data and more and more 5G, arguably it’s faster and as cheap as doing the transfer over a fixed network.
So, would be great to have such a feature…