We are suing a mail relay service.  for our domain.com

In order for the mail relay to accept the mail the from address must be  MyName@domain.com , which works to send emails to outside domains well.

the issue is the SMTP on the IBM i is marking any email to :  MyCoworker@domain.com Delivered to /QTCPTMM

This never makes it to the Microsoft 365 server for distribution which is our mail provider.

I have not found what setting I need to adjust to make this email be considered Outbound  not internal email server 

thanks,

Have you set following parameters...

CHGSMTPA FWDHUBSVR('office 365 relay')  
         MAILROUTER('office 365 relay') 
         FIREWALL(*YES)