Outlook will not connect to my SSL IMAP email host on siteground.com

Question

We have a SG115W. 
 Our host uses IMAP 993 and SMTP 495 - Outlook cant get to the mail isp. 
 I can browse web just fine and SSL works fine on the browser. 
 
 I can not get any emails through outlook. 
 Our firewall log shows ports 993 and 495 being dropped. 
 We cant seem to allow it in or out.

Scott_Klassen · Accepted Answer

These are non-standard ports, so you must have created custom service definitions for the services. Did you create them correctly, with the source port being 1:65535 and only the destination port being the custom service port (995 and 495)? Make certain TCP/UDP is correct. If these don't help, post a screenshot of the firewall rules and lines from the full firewall log showing the drops.

MSonic · Answer

I am having some issue with email that is racking my brain. 
 
 Recently a few pc's outlook stopped connecting to IMAP over 993. The work over non ssl ports 143 just fine. 
 Outgoing SMTP connection 465 work just fine but IMAP 993 fails. The crazy thing is it is not on every users pc. 
 Other PC settings of IMAP 993 SSL and SMTP 465 work just fine. 
 
 Thanks in advance for any insight you can provide.

MSonic · Answer

We have resolved the issue. It was not a UTM problem. Sophos support used Tcpdump to verify some internal host had incompatible IMAP SSL/TLS requirements that the mail host recently put in place without notifying customers. Changing mail client or upgrading host OS to Win 8 or 10 was the solution. Thank you for the assistance.