Timeout when downloading IMAP4 folders with more than 30,000 messages

[randolf]

Describe the bug
When a user tries to access a folder with more than 30,000 messages, after approximately 1 minute they are presented with a "Timeout" error message in large red text where the list of messages is expected to appear. (RainLoop doesn't exhibit this behaviour, so this is a show-stopper at the moment, but I'm hoping it can be resolved soon.)

Expected behavior
List of first 100 messages should appear in less than 1 second.

Please complete the following information:

• Browser: Current versions of Firefox, Opera, and Chrome all exhibit the same behaviour
• IMAP daemon: Dovecot v2.3.4.1 (64-bit) on Debian (Linux)
• PHP version: 7.4.3.3 (64-bit) on Debian (Linux)
• SnappyMail Version: 2.28.4
• Mode: standalone (manual installation)

Additional context
Mail server is a separate machine. Traffic is going over Gigabit Ethernet on a private subnet (10.1.1/8), without encryption, which is a physically separate network that's not part of any public-facing IP addresses and networks. (This means that SnappyMail is accessing IMAP4 over a Gigabit Ethernet link. RainLoop is too, and is not having this problem.)

Thanks!

[randolf]

This problem seems to have cleared itself up. I hope it doesn't come back.

[eeuak]

We also experience this issue altough only when clicking the folder the very first time. Second click on the folder and the contents are shown. So it is surely a loading timeout, the sync itself doesnt seem to run into a timeout.

[eeuak]

Is this already a known issue? Anyone has an idea for a fix?

[the-djmaze]

Please read https://github.com/the-djmaze/snappymail/wiki/Improve-performance