Is it possible to add UPN of one user as an email alias of a different user?

Question

Hi,

Not a O365 expert, so pardon if my question is imprecise.

The situation: each user must have an admin account for administrative work. That account should be able to receive email. At the same time it does not make sense to create a mailbox for each admin user. So idea is to add admin user UPN as an alias to a "real" user with a mailbox.

For example we have two users in Azure AD (sync'ed with on-prem AD):

1) Admin (UPN: admin@jaswant .xyz; no mailbox);

2) Mike (UPN: mike@jaswant .xyz; mailbox: mike@jaswant .xyz).

Can I add email alias admin@jaswant .xyz to user Mike? Any issues with that?

I am not sure if there is any internal check that the email alias "belongs" to an existing user (although that user does not have a mailbox).

I don't have access to the environment unfortunately and would appreciate if someone could quickly validate the idea :)

Please share your views.

Answer 1

that wont work, sorry. It will cause a sync error

https://learn.microsoft.com/en-us/azure/active-directory/hybrid/tshoot-connect-sync-errors#description

Azure Active Directory schema does not allow two or more objects to have the same value of the following attributes. (This is not an exhaustive list.)
ProxyAddresses
UserPrincipalName
onPremisesSecurityIdentifier
ObjectId