How to Access Office 365 Shared Mailbox from a Mobile Device and Send Messages

After hours of troubleshooting and internet research we finally identified a workaround which allows you to access a Office 365 shared mailbox and send messages as the shared mailbox as well.   First we are going to step through and review some of the problems identified with other fixes found during our internet research and identify the errors we had with these fixes.  Many of these fixes solved the problem as some point, but they no longer appear to do so. So if you are ready to skip the history and move straight to the workaround, you can skip to it here.

Solutions Tried with Little Success

Accessing an Office 365 shared mailbox has always seemed to be the easiest using Microsoft Outlook on the computer.  This provides the most functionality with shared mailboxes and allows you to access the mailbox relatively easily, even allowing you to change the address in the From field (assuming you have the proper permissions).  This function is used heavily by small businesses when staff members have to wear multiple hats and  support multiple public facing mailboxes for sales, support, etc., allowing their users to respond as the shared mailbox and not as their user account email.  This ensures any return correspondence is sent to the shared mailbox and not the individual user.

However, the shared mailbox functionality in Office 365 becomes more challenging as we increase our mobility into Outlook Web Access and even more so when we try to access directly from a mobile device.

From Problems to Functionality in Outlook Web Access

Once in Outlook Web Access (the web interface, not the OWA mobile app), we tested accessing a shared mailbox by right clicking on the username and adding it in as  a Shared Folder, similar to the process listed here by the University of Wisconsin at Milwaukee (see part 1).  With this method, we were able to access the shared mailbox as a shared list of folders, but when we attempted to send a message, we were unable to edit the address in the From field to send the message as the shared mailbox, our only option was to send from our user account email.

Just to clarify, let use an example.  My primary user account that I use to log in is:

My User Acocunt (Primary User Account)

I have a shared mailbox set up as follows:

Shared Mailbox

I have this shared mailbox with permissions set so multiple individuals can monitor the shared mailbox and reply to messages using “send as” so their responses show as coming from “” and not their user account “”.  We will continue to use this example as needed for the rest of this discussion.  Please note these emails are for demo purposes only and are not active emails.

In Outlook Web Access (the web interface), the only way we were able to access the shared mailbox and allow the sending of messages as the shared mailbox (i.e. send as “”) was to left click on the person icon in the top right of the webpage, scroll down, and click “Open another mailbox…”.  When clicked, we were prompted to enter the mailbox  we wanted to access (i.e. “”).  Once the shared mailbox was entered and verified to be valid, the Open button became available.  When clicked, the shared mailbox opened up in a new web browser tab appearing as its own mailbox.  This allows the user to run the shared mailbox as if they were logged in as that user.  By default, all messages sent from this new webpage are sent as the shared mailbox (using the example, messages would be send with the From field showing as “”).  It also allows you to customize the inbox just like any other user with the following features and more:

  • Add custom signatures
  • Automatic Replies
  • Clutter
  • Junk Mail
  • Read Recipts
  • Inbox and Sweep Rules
  • View Formatting (i.e. Reading Pane, etc)

Using this means in Outlook Web Access allowed us to restore most of the functionality available in the Outlook computer application.  However, accessing similar functionality on a cellular device proved to be quite  a challenge.

Office 365 Outlook Web Access (OWA) of Demo Shared Mailbox

Testing Shared Mailboxes with Mobile Phones

There are a number of different workarounds on the internet which used to allow access to shared mailboxes on a mobile device.  Some focused just of accessing the mailbox to read the email while others focused on just sending the email as the email associated with the shared mailbox.  This caused for multiple steps to access a single mailbox which can be quite cumbersome and inefficient.  Then starting at the beginning of 2016, many of these workarounds just stopped working.  It appeared that Office 365 upgraded their systems, blocking many of these methods.  at least all that we tried until finding our workaround (skip to our workaround here).

First we tried connecting a custom account in the iOS Mail application set up for IMAP with Office 365.  We tried a number of different methods using this approach, but the IMAP account always opened the primary users account folders and not the shared mailbox.  Then we tested this workaround provided by Slipstick Systems which was one of the best we came across.  It allows us to focus the mailbox to the shared mailbox and not show the users folders (i.e. just the shared mailbox).  This worked great for reading messages and accessing the folders, however, when the attempt was made to send a message as the shared folder (i.e. send message as we received an SMTP error stating:

Unable to Send Email
A copy has been placed in your Outbox.  The sender address “” was rejected by the server.”

iPhone SMTP Error

No matter what we tried, we were unable to send the email.  It appears that the Outlook 365 SMTP server will no longer allow a message to be sent through this protocol where the From email does not match the primary user account.

We then tried setting up another Exchange account on the iOS Mail Application.  Using the email address of “” and a username and password of our primary user account “”.  As we suspected, we were unable to create the account as we already have a exchange account set-up on the device for our primary user account.

iPhone Exchange Error with Shared Mailbox

At this point we looked for other options outside of the native iOS Mail application, which brings us to the OWA Application for iOS.

OWA App for Mobile Device

Once the OWA App for the iPhone(iPhone 5s to be exact) was downloaded, we started by completing Part 2 of the process listed here by the University of Wisconsin at Milwaukee.  Since we had the shared folder already added from the OWA Web Interface from Part 1, we logged in as listed in the UWM Guide using our primary user account (  Once the account was added, the shared folder did appear in the OWA application.  However when we accessed the folder, and accessed the “From” field to change the address to “”, there was no option to do so.  The “” account was not an option in the drop down.No Shares Mailbox Account OWA App iOS

So again, unable to send as the shared mailbox, “”.  At this point we started experimenting with the URL’s that were called when we opened up our shared Mailbox from the Outlook Web Access web interface.  A few cycles of trial and error and we discovered our successful workaround.

The Workaround

For the explanation of this workaround we will be using the following example as described previously in the post.

My User Acocunt (Primary User Account)

Shared Mailbox

We started by un-installing the OWA App from the iOS device and re-installing in order to ensure a fresh application.  At this point, when the OWA App was opened, we were prompted with the “Before You Start” screen.

OWA App Before You Start

After selecting Continue, we were prompted for our email address.

Email Address:

OWA App Config 1

Once entered, select Done, then press Sign In.  We were then received the “Couldn’t Connect” error.

OWA App Cant Connect Error

After pressing the Close button, we were then able to enter our password.  We entered the password for the primary user account (i.e. the password for “”).  Then press Done and Sign In.OWA App iOS Almost Login

OWA App iOS Almost Login 2

The OWA App then searches for the server…

OWA App Searching for Server

A “Couldn’t find your settings” notice appears, when available, press Advanced.OWA App Advanced Prompt

Next is where the fun begins, enter the advanced settings as follows.  Please note, I am going to use the example addresses described throughout this post.

Email Address:

Password: Password for the primary user account (i.e.


Domain: \


OWA App Advanced Settings 1

OWA App Advanced Settings 2


Then press Sign In.  The OWA application will then contact the server.

OWA App Contacting Server

If everything was entered correctly, you will then be prompted for Permission to Send Notifications on your device.  Select your permission setting.

OWA App Notifications Prompt

And you should be in your shared mailbox!

OWA App Shared Inbox Sucess

Only the folders located in the shared inbox will be visible, even though your are logged in with your primary user account credentials.  In addition, your default “From” address is that of the shared inbox as you can see below.

OWA App Shared Success - From

In addition, you can still search the Global Address List.OWA App Shared Success - GAL

You also have setting options allowing you to:

  • Set a default signature
  • Change sort order
  • Set message format
  • And more.

Again, many of the features seen in Outlook on the desktop or Outlook Web Access using the web browser are now accessible.

Problems Identified

Although we now have a workaround allowing us to send and receive messages as a shared mailbox, it’s not perfect.  In our testing we have identified that the OWA App has some issues which we have listed below.  If we identify any other issues, we will update to post to reflect the new information.

  1. Notifications Don’t Work – It is pretty much summed up in 3 words.  Regardless of how we manipulate the settings in the iPhone for the OWA app (i.e. banners, notification bar, etc.)(and yes, we did allow permissions for notifications) we can not get the OWA application to show them.  This becomes a large concern, as most people want to be notified soon after they receive an email in a shared mailbox.  Due to this, we have actually re-installed the IMAP workaround solution mentioned earlier in the post provided by Slipstick Systems in addition to the OWA workaround.  This allows the users to get notifications in the format they are accustomed to via the native iOS Mail application, but then use the OWA App to review and reply/send messages as the shared mailbox.
  2. The App Only Refreshes with New Mail When it is Opened – we have found this to be hit or miss.  But again, problem solved with adding in the IMAP solution mentioned previously for receiving email.
  3. Conversation View Can Not be Turned Off – this is a common thread of frustration regarding Outlook Web Access on all platforms including the app.  We just have to live with it for now until Microsoft gets a clue that many users don’t want to use it.

If you found this workaround useful, please leave us a comment to let us know.  To spread the word to others who may be experiencing similar challenges, please share the post using the icons below.