Bad Signature - Both Roundcube and Squirrelmail webmail cannot search for anything + cannot open many emails because there are more than 200, 000 emails in my Inbox

[Sam Kuper]

On Wed, Apr 20, 2022 at 09:51:18PM +0800, Turritopsis Dohrnii Teo En Ming wrote:
> I believe Gmail is using IMAP. The instructions for configuring Gmail
> email accounts in Outlook specifically mention IMAP server hostname:
> 
> imap.gmail.com
> 
> TCP Port 993, SSL

Gmail offers an IMAP2 endpoint so that users can connect to Gmail with
IMAP2 clients (Thunderbird, Claws, Apple's Mail.app, or whatever) if
they wish to.

However, Gmail's web interface, and Gmail's proprietary mobile apps,
almost certainly do *not* use IMAP2 to communicate with the Gmail
servers.  As has already been pointed out in this thread, they likely
use a proprietary protocol optimised for that proprietary environment.

Sam