TLS/SSL failure for mail.gandi.net: SSL negotiation failed

Hi,
I installed Projeqtor on Ubuntu.
I am trying to configure an imap access for ticket creation.
My mail provider is Gandi, and I entered {mail.gandi.net:143}INBOX as server .

I get the following error:
TLS/SSL failure for mail.gandi.net: SSL negotiation failed

What should I check to overcome this problem ? (Configuration ? Php version ? Openssl version ? ...)
Thanks
Franck

It didn't help.

Here is the log:
2022-10-17 09:40:37.773 ***** ERROR ***** [V10.1.2] ERROR *****
2022-10-17 09:40:37.774 ***** ERROR ***** [V10.1.2] on file '/var/www/projeqtor/model/ImapMailbox.php' at line (86)
2022-10-17 09:40:37.774 ***** ERROR ***** [V10.1.2] cause = imap_open(): Couldn't open stream {mail.gandi.net:143/novalidate-cert}INBOX
2022-10-17 09:40:37.909 ***** ERROR ***** [V10.1.2] Error connecting to Mailbox {mail.gandi.net:143/novalidate-cert}INBOX for This email address is being protected from spambots. You need JavaScript enabled to view it.
2022-10-17 09:40:37.909 ***** ERROR ***** [V10.1.2] TLS/SSL failure for mail.gandi.net: SSL negotiation failed

The environment is:
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=22.04
DISTRIB_CODENAME=jammy
DISTRIB_DESCRIPTION="Ubuntu 22.04.1 LTS"

php -v
PHP 8.1.2 (cli) (built: Aug 8 2022 07:28:23) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.1.2, Copyright (c) Zend Technologies
with Zend OPcache v8.1.2, Copyright (c), by Zend Technologies

Not sure what else I should look for...

I did succeed to connect with {mail.gandi.net:143/imap/notls}INBOX

But I think this is a security rosk and I'm sending my password in plain text, isn't it ?

Ok, I managed to get it working with SSL instead of TLS:

{mail.gandi.net:993/ssl}INBOX

Nevertheless, I asked Gandi for support on using TLS, just to understand. I'll keep the list informed if I get a relevant feedback.

Franck