I have the need to send email as a different user. My main email is firstname.lastname@example.org, however I need to send email as email@example.com
I have incoming email working...if I send to firstname.lastname@example.org or email@example.com, the email shows up in Outlook and all is well (Outlook 2016)
However, if I compose a new email, change the "From" to firstname.lastname@example.org and hit send, I get a bounce
This message could not be sent. Try sending the message again later, or contact your network administrator. You do not have the permission to send the message on behalf of the specified user. Error is [0x80070005-0x0004dc-0x000524].
Searching on Google indicates that I need to allow permission to do this in Exchange, but always seems to point to the fact that I need to allow permissions to another user...but since that user is me and doesn't have a separate account, I don't understand how to make that work.