I have an gmail account that I've had working with Mail.app via IMAP for years (now on High Sierra). I no longer have access to the gmail account, but I have all the email locally on my machine. I'm trying to figure out how to backup/export all this email locally so I can import it in to my fastmail account.
- Because I don't have access to the gmail account via the web, so I can't use Fastmail's excellent direct import tools.
- Exporting from Mail.app and then re-importing is only grabbing 5-10% of the messages. I think the ones that don't transfer are ones that have attachments? But there seems to be others without attachments that don't transfer so there is more to the story.
- All the email is still accessible within Mail.app itself.
- I can't drag messages/mailboxes/folders within Mail.app from the gmail account to either "On my mac" or my fast mail account. They simply do not copy.
I'm at a loss, any tips? Is there a way to copy everything for an account via the Finder?