I think I am not mistaken in saying that the original purpose of IMAP was to access a remote database, vs POP's approach to download it. When the IMAP client opens a folder, the server uploads the *index* of its content. When the client requests a specific item, the server uploads the item while keeping the original. If the client renames a folder, the server just renames the folder.
Apple Mail behaves like a POP client that wants to download everything while keeping the db on the server. Further down Apple's madness, if the client renames a folder, Apple mail asks the server to upload the full content of the "new" folder. Batshit crazy!
The very best therapy here is, in my opinion, to serve Apple Mail's request for mass download as if it were a regular IMAP index request, if technically feasible. If it is not feasible, then the alternative is not to rate limit the connection, but to ban Apple Mail entirely.
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On Tue, Oct 31, 2017 at 2:46 PM, Rupert Gallagher <ruga@protonmail.com> wrote:
Aki, the IMAP client can receive the e-mails with an empty body without any damage. This is how IMAP works normally. The full body is queried again by the client when reading the e-mail for real.
On Tue, Oct 31, 2017 at 1:52 PM, Aki Tuomi <aki.tuomi@dovecot.fi> wrote:
What's in your mind as solution?
When dovecot receives many full body downloads from a client, it could respond by sending the header only.
This sounds rather dangerous. Client is expecting full body download, not headers. Aki