Exchange & SBS basics: how does user B send as user A? What am I doing wrong?

This either never came up before for us or a long time ago.
User A is on vacation but getting mail on their phone
User  B wants to send as that user to a customer

we don't know user a's password. I could change that in the SBS 2011 and user b logs in and sends as them in OWA or similar. But that would break his email on his phone and require talking to him on vacation. Don't want to do that and that is low tech way.

Some googling, I go into EMC, server, recipient, mailbox and added user B using action on the right side 'manage send as permission' to user A - or do I have that backwards?

User B closed & opened outlook.  Clicked on from button, typed user A name and tried to send to her personal email as test.  it failed - you don't have permission.

Repeated steps adding user A to user B's 'manage send as permission'. Repeat and still failed.

Tried "manage full access permission" on user A's account and still failed.

Does it take time to update in exchange?

Am I doing something wrong?

Then once they send as user A, how does user B see user A's mailbox for the reply?
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

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.

Pete LongTechnical ConsultantCommented:
In user Bs Outlook  profile - Add User A's mailbox as an additional mailbox to open.

Mal OsborneAlpha GeekCommented:
"Send as" and mailbox access are separate things.

To "send as" another user, you need to grant that permission. In this instance, you modify the properties of UserA's mailbox, to grant UserB "send as" permissions. ie, you got it right the first time.  UserB should then be able to add the "From" field in Outlook, type in UserA's address and send as though the message was from them. It usually just works.

There are a few ways that UserB can access UserAs mailbox. You could grant UserB owenership of the entire mailbox, and add it to their profile in Outlook. (Using newer versions of Exchange and Outlook, by default a UserB will automatically have UserAs mailbox added to their profile once granted ownership, but I forget which versions of both are required.)

Without involving an admin, USerA can also, using Outlook, grant UserB various levels of access on a folder by folder basis.   This is commonly done for the Inbox and calendar. Once granted some permissions, UserB can just use File, Open, Other users folder to view the folder.

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
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

From novice to tech pro — start learning today.