Posted by Gary Garber, Last modified by Alan Rusek on 03 June 2015 10:13 AM
OS: Windows; IceWarp Server Version: 11/10
You will need to check these locations of Icewarp Server Administration to ensure there is no maximum size set.
Go to Domain & Accounts > Management and you will need to check per domain, group, mailing list or user the following :
Limits Tabs then in Users section Max message size
Also you can check too in Mail > General > Delivery tab in the General section Max message size