shared mailbox default "send-as" ID in outlook

Occasional Contributor

I have a shared mailbox "info@" with a planned four users in O365. "guy@", "craig@", "alex@" & "ray@". Currently, only my account "guy@" is linked, and includes send-as permissions.


I notice that if I use webmail from the shared mailbox, then I'm sending as "info@", but if I use my outlook client, I'm sending as "guy@" by default. I need to select "info@" each and every time I create a new message. This is very cludgy and is no good for my colleagues.


How do I create a simple set of instructions for my colleagues to set up their computers so they can set up the shared folder, and send-as "info@" by default - or am I better off telling them just to use webmail?


19 Replies

That depends on the method you have used to add the shared mailbox in Outlook. If you want to send as the shared mailbox account by default, your best option is to add it as additional account (via File -> Add account), as opposed to adding it as additional mailbox or using automapping.

My worry is that when I add the account manually then there will be two “accounts” in outlook with the same name, including the auto mapped one.
Is there a simple way to disable the automapping, so I don’t have to mess about with powershell (which I’ve never used before)?
I’m guessing that send-as is a main selling point of shared mailboxes, that clients like outlook should support it natively.

You can only remove the automapping via PowerShell, no other way around it.

So safe to say that for Microsoft users to use “send-as” from their Microsoft client, they expect users to get to grips with powershell.
My pc doesn’t have admin rights, so hoping powershell is something that doesn’t need install rights.

You can use Send As just fine with automapping too, you simply have to change the address :)


Or you can simply create a separate Outlook profile with just the shared mailbox and use it when necessary.

I might be wrong but I thought once you had turned on the From field in the Outlook desktop client and selected the shared mailbox, you don't need to do that again in future - it'll just be available as a drop down option - I don't think this is too bad?


I would also suggest you set the properties -MessageCopyForSendAsEnabled and -MessageCopyForSendOnBehalfEnabled to $True as by default, messages sent by delegates of the shared mailbox will be kept in the delegates mailbox so others won't be able to see these items.


With this change a copy will be kept in the shared mailbox too. This can be done via PowerShell once you have made a connection to your tenant.


Set-Mailbox –Identity 'Customer Services' –MessageCopyForSendAsEnabled $True –MessageCopyForSendOnBehalfEnabled $True



The shared mailbox wasn't available in the "from" drop-down field, so I had to select "other", then select it from a list of O365 mailboxes. I had to do this multiple times, so I don't think the O365 shared mailbox name was moved across to the "from" list at all. Obviously, I don't want my users to have to do this every time they want to send a mail, as they are not all that "computer friendly".


Similarly, I want the setup for them to be as painless as possible, and I had hoped that automapping would make that so, but it seems they will have to set up their email accounts the long way around, by themselves. I don't want them to make the mistake of sending from their personal accounts when they should be sending from the shared mailbox.
I'll give powershell a go just now - assuming I can do that on this machine, which I don't have windows admin rights on.



Be sure, the first time, to select the shared mailbox address from the GAL (i.e. do not type it!).

Then the address will be available in the "From" dropdown list.

If you don't find it in the dropdown list, then double check your steps, because it should definitely work... ;)

Yes, I seem to recall having to select 'Other' and then locating it in the list but once you've done that, it should be available in the From drop-down list.

Automapping works fine, I'm not sure what your problem is exactly. Might be worth bearing in mind the other issue/limitation that I have discovered, although I'm waiting on some confirmation that this is a Office 365 issue and not just for my tenants. See and

I don't think you need to be a Local Admin to connect to your tenant, you'll want to use the following to establish a connection:

$UserCredential = Get-Credential

$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri -Credential $UserCredential -Authentication Basic -AllowRedirection

Import-PSSession $Session

Hello gcc info,

If you are using only Outlook but not OWA interface you can search for a third-party add-in that auto-populate the From: field. 



Found any 3rd party addins for that yet?

@Haneef Ibn Ahmad wrote:
Found any 3rd party addins for that yet?

Yes.  SetFrom, for example.

@gcc info 

Same problem here, where customers don't want to manually set the from adress to the shared mailbox address for new mail when shared mailbox is already selected. 
Since the workaround below is not suitable for accounts protected with MFA I voted on the uservoice:  

Set shared mailbox as default send address in Outlook

Please vote to support this feature request. ;)

Hi @Vasil Michev ,


In this issue you are mentioned as the one who has a workaround? Would you please help me with it?


I've a small environment with 6 users and one shared mailbox. The users only sent mail from the shared mailbox so they don't want to change the send from address everytime.

I'm a dutch guy so maybe the english part of my language isn't that good, srry for that :-).


The current setting: (users are joined the shared mailbox in the admin center). So Outlook auto mapped this mailbox to the users. If I try to add the mailbox as a new account, it won't appear..:-(.


So I need some help..


Thanks in advance!








@IMDutchReferring to Vasil Michev reply at11-29-2017 10:46 AM. "If you want to send as the shared mailbox account by default, your best option is to add it as additional account (via File -> Add account)"

The way to add an additional account as the functional mailbox account itself is by adding it as a new mailadress using the UPN of the functional mailbox (for example in Outlook. You might have to reset the password and enable the account to do so.
(So, nót using the option to 'Add another mailbox' option as part of the account of the user as part of the advanced options) 

Hopefully this explains the workaround you are looking for in more detail. But please vote as requested since this workaround is not compatible if you want to enable MFA on all accounts.


I had to switch users from logging in to a mailbox via Username/password to a shared mailbox due to there being too many users logged into the user box.  So that will no longer work as a work around for needing a default sender.

Hi @IMDutch,


have a look at RightFrom add-in - it does exactly what you want. 

@Vasil Michev 


When I forward a task created in a shared mailbox, If I could set the default "from" ID in Outlook as the user ID(my address) and not the shared mailbox's ID.