impossible to configure automatic ticket from mails

Hello,
I've been stuck on automatic ticket configuration via email for a while.
Whatever the configuration, I am left with an error message in the logs.

need help plz :/
2021-01-15 14:38:00.983 ***** ERROR ***** [V9.0.2] ERROR *****
2021-01-15 14:38:00.983 ***** ERROR ***** [V9.0.2] on file '/var/www/html/projeqtor/model/ImapMailbox.php' at line (86)
2021-01-15 14:38:00.983 ***** ERROR ***** [V9.0.2] cause = imap_open(): Couldn't open stream imap.webmail.************.fr:993
2021-01-15 14:38:00.983 ***** ERROR ***** [V9.0.2] imap_open(): Couldn't open stream imap.webmail.****.fr:993 in ImapMailbox.php at line 86
2021-01-15 14:38:00.984 ***** ERROR ***** [V9.0.2] Error while executing CRON script : fix the source issue and manually restart the CRON Process
2021-01-15 14:38:00.984 ===== TRACE ===== Cron::run() - Error on checkEmails()

Hello,
thank you for your help.
The problem was with the connection string. The imap does not work internally.
I now have another problem, tickets are created endlessly ... (the same email will create a ticket every 10 seconds .. and I don't understand why)

I had this doubt too.
So I put a rule "marked as read" to each email received automatically. Unfortunately, it does the same.