we have been running a 3rd part monitoring app (KnowledgeSync) with Exchange for a few months without error. Last week on the same server we needed Excel and installed it with MS 365 Apps for business. Ever since the email processes fail with a message of "the server does not support STARTLS (STLS for POP3) command. tried turning TLS on and off. Same error message.email error.docx any ideas what MS 365 apps might have changed to cause this error?