Issue in sending out email from Service Desk Plus

Issue in sending out email from Service Desk Plus

There is an issue faced recently at the Service Desk:

  1. When user creates ticket, no email being sent to the Technician Group.
  2. When technician reply email, cc to any group/individual users, the email not sent out. Below error displayed.


I am able to send sample email from the mail server setting for outgoing, and also able to reply to tickets when no email address in the cc tab. Please help.