as title, e.g. i have a domain a.com and reg it on office 365
i can send mail from user@a.com, then i added a secondary domain b.com on office 365 (default domain still a.com)
then, now i can receive mail which send to user@a.com and user@b.com,
BUT, i can't use user@b.com as "from address". i just can use user@a.com send mail only.
i want to use a.com and b.com as sender domain, how to do that ?
many thanks!!!
