Fortunately, it is very easy to reply to a message as a linked topic. Just tell Discourse you want to do so via the button in the upper-left corner of the editor panel.
I don’t think it’s actually that complicated.
Assuming the server supports folders (which any IMAP-capable server will), it is really just two networking protocols that access the same data.
When using IMAP, your client uses that protocol to perform all the standard actions, including:
Query the set of available folders
Query the set of messages in a folder
Read a message
Write a message
Move a message between two folders
Delete a message
When using POP, the client uses its API, which is more limited. POP typically can only access messages from a single folder (usually the “inbox”). Its commands will include:
Query the number of messages
Download the message headers
Download a message (with or without deletion from the server)
Delete a message without downloading
Note that all of these protocols are for reading mail. For sending mail, client apps usually use SMTP. Which may actually be running on a completely different server.
Thanks for the heads-up re: replying as a topic — I had not discovered that.
My shortfall of understanding on the POP and IMAP protocols has mostly been around how the file/data management works on the server. You state they both access the same data, which is the source of my curiosity and uncertainty. For example a POP account can be configured to delete new messages immediately after they have been checked for and downloaded—doesn’t that preclude a later check for the same messages on an IMAP client? Similarly, but in the other direction if an IMAP client checks the inbox and then moves one of the new messages into another folder, won’t that prevent a later check by a POP client from seeing that message that is no longer in the inbox?
These protocols are designed to do different things and have inconsistent sets of configuration possibilities. This does not seem simple or obvious.
And then there’s webmail, but let’s not further complicate this.
Yes. Once they’re deleted from the server, they’re not there and IMAP won’t have access to it.
If you were to use both on the same account, you will probably see some weirdness. The download-delete that POP does will cause the message to vanish from all IMAP clients’ server-side folders.
And if an IMAP user moves the message into a server-side folder, POP clients won’t see it. And other IMAP users will see the message vanish from the inbox and appear in the folder.
It’s no more complicated than IMAP. What you see on the web site is what you see on the server. If you make a change there, all clients will see it. And if the message is moved out of your inbox, POP clients will no longer see it.
And if a POP client deletes the message (with or without a download), it will disappear from IMAP and web clients.
You’re overthinking it. There is only one truth here - the state of the server. All these different protocols manipulate that state.
It’s just like a cloud-based document. Take, for example, a Microsoft Word file on a OneDrive/SharePoint folder. If you edit it with the desktop app, the server-side document will change. If, later on, you edit it (maybe from a different computer) with the web-app, that modifies the same document. When you later return to the desktop app, you will see the changes from your web-app edits.
Going back to the original message that started this:
I believe that the warnings about deleting a mailbox go back to the origins of the POP protocol. By default, mail clients that used POP would download all waiting messages and delete them from the server. There was an option to download and not delete, but that was not the default behavior IIRC. So when you delete a POP3 account from Apple Mail, it’s warning you that deleting the account and its associated mailbox may delete all of the messages that were ever downloaded anywhere.
Yes, and I believe that was established in that thread.
POP downloads all messages, and typically deletes them from the server afterward. So your only copy is stored locally in your mail client.
When deleting an account from a mail client, all local folders associated with that account typically also get deleted. If your messages are in there (that is, if you didn’t move them to a folder not associated with that account), then they will be deleted.
The Apple Mail warning sounds completely reasonable to me.
There’s a new protocol to replace IMAP: JMAP (JSON Meta Application Protocol, which sounds like a backronym). It isn’t well supported yet. Fastmail supports it, and were instrumental in developing the standard.
The JMAP site gives a long list of advantages over IMAP: Why JMAP?