No email on first access

[Bables55]

Describe the bug
I updated from 2.27.2 to 2.27.3 and when I logged into my account with SnappyMail for the first time in a web browser, there were always no emails at first, then after a while the emails started showing up.
Is there a feature like past cache view missing in 2.27.3?

To Reproduce
Steps to reproduce the behavior:

1. Log in to SnappyMail via PC or Smartphone

Expected behavior
A list view of the last received email.

Please complete the following information:

• Browser: Any
• IMAP daemon: Courier
• PHP version: 8.0.27
• SnappyMail Version:　2.27.3
• Mode: standalone

[the-djmaze]

The problem here is speed.
Web requests timeout after several seconds, but the process to index mail is still busy.

I have some ideas to solve this, but no definite yet due to all different server configurations.

[the-djmaze]

Follow #1071 as this issue is related to that one