Older product versions may not resemble the screenshots below.
ESET File Security for Microsoft Windows Server (EFSW) is specifically designed to replace ESET NOD32 Antivirus Business Edition and ESET Smart Security Business Edition for use on servers (domain controller).
We are running MS Office home & business 2010, 2013 & 2016 which are all experiencing this issue.
Only continue with Part IV (the uninstallation of ESET NOD32 Antivirus or ESET Smart Security Business Edition) if you are able to restart your server at this time.
Also, guessing OWA is on the web (external) and outlook is local which means it's a local network issue, which other internet connections have you tried on?
Check the reg sizes are set OK or not set: Open the registry editor and browse to: Outlook 2016: HKEY_CURRENT_USER\Softwarees Then add a new DWORD value: Maximum Attachment Size Unlimited message size uses a value of 0.
After your computer has restarted, repeat steps 2-4, Clear should now be active.
We contacted out internet service provider to check the firewall and MPLS setup to see if anything was limiting sending emails but no thing has found to be causing that.