I am not quite sure if it is even problem od my 790 appliances, but it happens only in our offices. Every so often Outlook IMAP connections get blocked on sending / receiving emails. When it happens, progress bar freezes in half. After that I cannot close Outlook in ordinary way and I have to do it by task manager killing process. Next start everything works correct but only until next stop.
It started many months ago, but first I thought it will go with next MS Office update. Time is running out and still many different versions of Outlook perform not better.
This does not happens outside office, not on every station but in all offices where we have 7x0 appliances.
Our mail server is hosted by ISP.
I have IPS, Anti-Virus, Anti-Bot and Applications & URL Filtering activated while Anti-Spam, Threat Emulation, QoS not and SSL Inspection set to HTTPS Categorization. I have also standard policy set on FW and other blades. I block security risk categories and "other undesired applications".
Does anyone suffers from similar problem and knows solution, please?