Use Thunderbird on the PC. Connect your old account, move/copy the messages to the local folder. You can even move the messages to the new email provider if you also connect the new provider with Thunderbird.
I would definitely do large migrations like this on the PC.
K-9 is not meant to be used for long-term email storage. Don’t use it for that. You won’t be able to extract your emails. To store mails, use a PC. A PC also doesn’t get lost, broken, or stolen as often as a phone.
K-9 has no way to export old emails (and probably won’t get one in the near future). If you get a new phone and the messages are no longer on the server, you cannot migrate them. We actually get quite a few support requests about this over at the K-9 forum. So telling users to use K-9 for long-term storage (when messages are deleted from the server) is not a good idea
Doing it on PC as suggested in other posts is the best way to do it. On Android you could use Termix and install some email fetching utility to achieve the same but keep in mind you need to backup the emails to some external media for archiving, whether you do it on a PC or Android/Termux
K-9 is not meant to be used for long-term email storage.
K-9 has no way to export old emails (and probably won’t get one in the near future).
If you get a new phone and the messages are no longer on the server, you cannot migrate them.
to use K-9 for long-term storage (when messages are deleted from the server) is not a good idea
I had incorrectly assumed if I downloaded all my emails with K-9 to phone, it would be a useful copy, in case something went wrong with my email provider. Now I learn there is no way to export those emails to migrate. Lock-in. Big mistake.
Also, the K9 acquisition into Mozilla/Thunderbird/Firefox seems to be moving away from unix philosophy of doing one thing well, towards a “non-profit” conglomerate trying to do many things.
I wouldn’t consider that flaws. K-9 wants to be your mobile companion to your desktop client. It does not want to be your only email client. That’s basically the design decision behind it since many years. If you use it for what it is made for, it works great. If you want to use K-9 as a backup solution, it’s not the right email app choice for you. Not being the right choice for you doesn’t make it a bad app
Example? I can’t think of any “conglomerate” feature that was added in the last few years.
Some people have desktops. Developers have desktops. Cubical slaves have corporate desktops. However, desktops are declining, and many people do not have desktops. Check out some statistics.
K-9 wants to be your mobile companion to your desktop client.
Did not see this anywhere else. Not in app description. Not at app website.
I see stuff like:
K-9 Mail is an open source email client focused on making it easy to chew through large volumes of email. (k9mail.app)
Full-featured email client
K-9 Mail is an open source email client that works with basically every email provider.(f-droid)
OK, thank you so much for all your thounghts…
In the end I will have a mail provider just for those both old email accounts to upload them to which will be a normal online provider…
Let’s call it a “Storage Provider”…
I will use my real new mail provider just for email from now on…