How to send an email from office 365 using an alias

Realized we can't send out from an alias email address using Office 365 / Online Exchange. Well, we can choose to do so but external recipients see our primary SMTP address. I made the alias primary SMTP and waited a bit but same thing. I then removed the alias and created a Shared Mailbox with the alias as the primary SMTP and waited a bit but surprisingly external recipients still saw the primary SMTP from our "main" account.

For example, I removed from my user / email account and created a shared mailbox with as the primary SMTP email address. I received a UPN error when trying this so I simply changed the display name on the shared mailbox to "Me Alias Domain" from just "Me" (which matched my primary account). That worked to create the shared mailbox and the me@aliasdomain email address could be typed into Outlook and used to send an email. Internal recipients saw the alias domain but external recipients saw the primary domain email address.

Any ideas how to send out from Office 365 using an alias without a third-party tool are much appreciated.
king daddyAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

David Johnson, CD, MVPRetiredCommented:
Don't even think of using this.. Spammers would love it.
What is your purpose?
king daddyAuthor Commented:
We need to prove we "own" a domain. Registrar records were not good enough (the person needing to do this requested the records from us - IT - which we provided and he sent along to the other org but they wanted an email from the domain we are claiming to own - which we obviously do). May sound crazy but he forwarded the emails to us that he received from them stating all of this.

Thanks for the reply
David Johnson, CD, MVPRetiredCommented:
Add a mailbox just for this and delete it after a month.
Your Guide to Achieving IT Business Success

The IT Service Excellence Tool Kit has best practices to keep your clients happy and business booming. Inside, you’ll find everything you need to increase client satisfaction and retention, become more competitive, and increase your overall success.

Vasil Michev (MVP)Commented:
There are add-ins that allow you to send as alias easily, but since you dont want to use them, the approach you described above can be used. Once you create the new recipient with the alias in question, you need to also grant Send As permissions (not send on behalf) and make sure to send AS the alias (select the address directly from the GAL, dont use any stored From or auto-complete entries). Or you can make it simpler by creating a regular user mailbox for said alias, then login directly with the credentials for that mailbox and send the message.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
king daddyAuthor Commented:
Thanks David, I guess I am going to do that.

Thanks Vasil. I created a shared mailbox and used the alias as the primary SMTP but when the user sends the email out it still shows his primary SMTP from his primary domain and not the alias domain. I wonder if that is because the shared mailbox is opened in his primary domain's outlook. Weird thing is we have several shared mailboxes with lots of people having full access as well as send as, and the shared mailbox is open under Outlook, and they do not have this issue of the primary domain / email address showing externally.

Could it be an issue with the Display name in EAC and Office 365 being the same for both the shared mailbox (alias email address) and his primary mailbox (primary domain email address)?
king daddyAuthor Commented:
OK I just tried again and, taking Vasil's advance to choose from the GAL instead of autocomplete, it worked.

Thanks all.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft Office

From novice to tech pro — start learning today.