Hello,
I have deleted accidentally mails (about 1000) on my desktop. I still have them in my POP3 in K9. Is there any possibility to upload them by IMAP or import them to thunderbird on desktop?
I’m willing to donate if a solution is possible.
Also, should I upgrade to “thunderbird android” to have this possibility?
kind regards
Other than forwarding each of those emails to an inbox, they are effectively gone. Neither K-9 or the forthcoming Thunderbird for Android support exporting emails.
thank you. Would it somehow be possible to use IMAP to upload them to the mailserver?
Sorry, it is not possible to change type of an account from for example POP to IMAP.
This and the lack of export capability are two very compelling argument to never use POP. At least not with K-9. Actually I think that K-9 and Thunderbird for Android should have VERY prominent warnings when configuring a POP account.
I use POP because I don’t like to store my mails in a cloud. I am very unfortunate that there seems to be no solution. Seems I have to forward small part of the mails.
Of course I had a backup, but i overwrote it by accident.
Which Android version are you on? If it is old enough and you do not have enabled storage encryption, you can ADB backup the K-9 database. That backup can be imported in an AVD, Bluestack or similar. That way the forwarding can be a) done on desktop and b) partly automated.
I’m on recent android. Encryption is enabled. So no way. I already searched for the database.
android/data/com.fsck.k9/files is empty.
What does the cloud have to do with POP?
I’ve been using IMAP for years now and NONE of my emails are kept in any cloud. I download them to my PC with Thunderbird and move them into storage folders. Those aren’t set up to sync of course, so once emails are moved out of the default folders like Inbox and Sent they’re gone from the server and only available locally on my PC.
So you say the default folders are synced with the cloud.
Only those 4 or so, Inbox - Sent - Drafts - Trash I guess. But I can’t imagine anybody NOT moving their emails out of those folders for storage? 
I am sure that many of us have ALL email on server using IMAP.
And let me say once again, because I think this is the most important takeaway here, a message to the devs: I think that K-9 and Thunderbird for Android should have VERY prominent warnings when configuring a POP account.
Also, K9 should provide a migration from POP3 to IMAP