When I download an attachment (“download complete message”) it’s apparently saved in K-9 Mail’s private storage. I “save” this attachment to my SD card and no longer need it in K-9 but it stays there and hogs internal storage space. I’ve got a couple GB used up by pictures and such, of which I already have copies on the phone.
Is there another way of clearing this memory aside from deleting the e-mails or reinstalling K-9? I’d prefer to keep the emails with which the attachments came.
Assuming you are running 5.600 and your account is an IMAP account, you could use the “Clear messages” feature to wipe your local sync database while leaving the emails intact on the server.
Configure K-9 Mail to only download a couple of messages (Settings > [Account] > Fetching mail > Local folder size). Then make sure to regularly sync that folder so old messages will be removed from the device (either manually or via Settings > [Account] > Fetching mail > Folder poll frequency).
“Clear messages” can be found under Manage folders > [Folder] > (overflow/three dot menu) > Clear local messages.
Thanks, I’ve cleared and redownloaded all messages. (I like to keep all messages locally so that I can look them up whenever I want.) That brought the usage all the way down to about a hundred MB.