The default SEND_MAIL command uses semicolons (, but if SEND_MAIL_DEFAULT points to a Windows Agent, multiple attachments fail unless a comma is used.
Release : 12.2, 12.3
Component : AUTOMATION ENGINE
This is fixed in the following releases:
Automation.Engine 12.3.0,
Automation.Engine 12.2.3,
Automation.Engine 12.0.9,
Automation.Engine 12.1.6