Problem accessing IRedMail mail server?

Question

Squid

After installing the Dr.Web antivirus on an Ubuntu server (with IRedMail installed), at first the web mail muzzle hung wildly, then it was not possible to access mail from client computers at all. A squid and freeradius proxy server is deployed on the system.
There is access to mail only from a local mail server, and letters are exchanged with third-party domains. The only problem is that it is not possible to get access to mail from any other computer.
When trying to connect to the mail through the browser, an error like Unable to connect.
/var/log/squid/access.log ----- 1631857933.258 0 9*.1*3.1*4.2*3 TAG_NONE/503 0 CONNECT mail.mydomen.ru:443 mav HIER_NONE/- -
If you need clarifications, logs, write. Please respond as much as possible!