We use KES 11 and Thunderbird Mail, and KSC.
Today, "File Thread Protection" module has begun to block mail sending.
If i disable File Threat Protection -> mail sending OK.
If i enable File Threat Protection -> mail sending not OK, Thunderbird freeze, but as soon as i disable "File Thread Protection" the Mail delivery will be successful.
Windows 10 ver: 1803
KES 188.8.131.5299 Localization: HUN