Oh, sorry. As a new user, I was not familiar with the customs.
OsTicket v1.15.8 (0daca43), PHP 7.4.30, mySQL 5.7.39 on Apache
IMAP+SSL / Port 993 / imap.gmail.com
Insecure applications are released; sending mails is possible without any problems.
There are no mail fetch errors in the log file.