How long will K9 support POP3?

I have just read a post that POP3 support will most likely be removed in the future. See Feature suggestions - #4 by cketti

Have installed the latest K9 and all we are looking for is an email app that can do POP3 and SMTP, delete the mail from the server, and have the local email deletions manually controlled.

Email servers support both POP3 and IMap. There is no credence to the suggestion that POP3 will be phased out and replaced by IMAP. That sort of rhetoric is usually spun by software limitations.

We also need to create new folders and move emails between folders. Can K9 do this ?


As far as I can tell, nobody said that. POP3 and IMAP have very different use cases. K-9 Mail is mainly supporting the “messages are stored on the server, everything local is just copies” model. When using POP3 this breaks down fast. For example, when a message is deleted, the local copy is moved to the local Trash folder, and the message on the server is deleted. There is no way to “undo” this operation. K-9 Mail doesn’t properly support local messages. So moving the local message from the Trash folder to the Inbox is not supported. Even if we supported that, with POP3 there’s no way to upload the message back to the server’s inbox.

Most of these are issues that can be solved by properly supporting local messages (and giving users a way to distinguish local-only messages from ones that are a copy of a message on the server). This comes at the cost of a lot of additional complexity. And as explained in the other thread, it comes at the cost of being the single store for (some of) the messages.

There’s way too few people working on K-9 Mail. So prioritizing is important. These days POP3 is a niche protocol. And in my opinion, even just keeping POP3 support as it currently is, will require more development and support effort than simply removing it.


The idea that POP3 deletes mail on the server when deleted on the client, and thus you can never take a message out of the trash is not correct.

Yes, of course it CAN work that way, but I have all my POP3 clients set NOT to delete on the server, EVER, except for the one on my main machine, which I consider the master. I can remove a message from the trash at any time, on all clients, including on the master, EXCEPT for K9 mail.

I guess it comes down to whether one considers an email to be some kind of unique ‘object’ that has one life on all clients (the way IMAP seems to want to treat it), or instead, a pile of text and headers that might be in any folder on any number of clients. The latter is how it works on most clients that do POP3. For these, a POP3 email is not a unique object, and they don’t try and treat it at such.

If POP3 is the next pillar that’s to be knocked down in K9, perhaps it really is time for a proper fork.

I have enjoyed this wonderful piece of software, the product of people’s good and hard work. It’s worked most reliably for about as long as I’ve had a smartphone, and I appreciate that I got a great program for free. Thanks.

However, you seen bent on removing the things that made it good and special, that differentiated it from the other apps out there. Not what I want out of K9 or any other client. I hope you’ll consider your users’ needs for their email client as you go forward.


Without POP3 this app is useless to me. It looks like my phone refuses the ‘upgrade’ for a reason (it crashes and reboots every time I try to upgrade).

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It doesn’t work like this, at least, not with my pop3 accounts.

see: Is POP3 still supported in K9?