Configuring an Exchange service account

The MyTimetable calendar push integration is able to connect to a user's calendar using service accounts. This page describes how to create a service account and how to grant calendar permissions to this service account. MyTimetable will then be able to access calendars without explicit consent of a user.

This page applies to both Microsoft Exchange (on-premises) and Microsoft Office 365.

Office 365 / Azure AD prerequisites

The following installs are required when managing Office 365 / Azure AD through Powershell.

The Microsoft Online Service Sign-in Assistant for IT Professionals RTW.
The Azure AD Module for Windows PowerShell:
- Azure Active Directory Module for Windows PowerShell (32-bit version)
- Azure Active Directory Module for Windows PowerShell (64-bit version)

You must be a tenant admin on your Office 365 tenant to run the cmdlets.

Global steps

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Creating a service account

A service account is needed to access the user's mailboxes. An account can be created in your on-premises Active Directory, or in Azure AD.

On-premises Active Directory

Using Active Directory Users and Computers

Add a new user in the OU where you would like to place the service account.
Enter a username, for example "sa-mytt-exch@eveoh.onmicrosoft.com"

Enter a password for the service account and make sure the password does not expire.

Using Powershell

Create a new AD user using the New-ADUser cmdlet. Replace the parameters to match your situation and preferences:

PS C:\> New-ADUser -Name "SAMyTTExch" -DisplayName "MyTimetable Exchange Service Account" -UserPrincipalName "sa-mytt-exch@dev.eveoh.local" -AccountPassword (Read-Host -AsSecureString "Password") -PasswordNeverExpires $true -ChangePasswordAtLogon $false -CannotChangePassword $true -AccountExpirationDate $null -Enabled $true -Path "CN=Users,DC=dev,DC=eveoh,DC=local"
Password: *******

Azure AD

Using the Azure Management Portal

Visit the Microsoft Azure Management Portal at https://portal.azure.com, using the credential of your Microsoft tenant that has the subscription to Office 365 you wish to use.
Click "Browse all" to browse all resources.
Click "Activity Directory". You will now be redirected to the classic Azure Management Portal.
Click the Active Directory you would like to manage.
Click "Add user" in the bottom bar.
Select "New user in your organisation" as type of user, and enter a username (e.g. sa-mytt-exch).
Enter a first name, last name and display name. Select "User" as role. Do not select "Enable Multi-Factor Authentication".
Click "Create" to assign a temporary password. Write down the password.
Logout from the Azure Management Portal.
Go to https://login.microsoftonline.com/
Login in using the account you have just created, and set a password for the service account.

Using Powershell

Create a service account using the following Powershell command. Of course you can also create an account in the Azure Portal.

Open the Windows Azure Active Directory Powershell prompt
Connect to Microsoft Online Services using your tenant admin account:

PS C:\> Connect-MsolService

Create the service account. Replace the "UserPrincipalName" and "Password" parameters to match your situation and preferences:

PS C:\> New-MsolUser -DisplayName "MyTimetable Exchange Service Account" -UserPrincipalName "sa-mytt-exch@eveoh.onmicrosoft.com" -Password "xxx" -PasswordNeverExpires $true -StrongPasswordRequired $true

Assigning an Exchange Online license (Office 365 only)

The service account needs to have a Exchange Online license assigned.

This step is only required when using Microsoft Office 365

Using the Office 365 Admin portal

Open the Office 365 Admin portal.
Click "Users" -> "Active Users".
Click the service account you have just created.
In the right bar, find "Assigned license" and click "Edit".

Click the license you would like to assign. Make sure "Exchange Online" is checked.

Using Powershell

Open the Windows Azure Active Directory Powershell prompt
Connect to Microsoft Online Services using your tenant admin account:

PS C:\> Connect-MsolService

List your Office 365 plans. Pick the AccountSkuId you would like to use.

PS C:\> Get-MsolAccountSku
AccountSkuId                    ActiveUnits     WarningUnits    ConsumedUnits
------------                    -----------     ------------    -------------
Eveoh:DEVELOPERPACK             1               0               1
Eveoh:ENTERPRISEPACK            5               0               2

List all service plans that are included in your Office 365 plan. In this case, the EXCHANGE_S_ENTERPRISE service plan refers to Exchange Online.

PS C:\> Get-MsolAccountSku | Where-Object {$_.AccountSkuId -eq "Eveoh:ENTERPRISEPACK"} | ForEach-Object {$_.ServiceStatus}
ServicePlan                             ProvisioningStatus
-----------                             ------------------
INTUNE_O365                             PendingActivation
YAMMER_ENTERPRISE                       PendingInput
RMS_S_ENTERPRISE                        Success
OFFICESUBSCRIPTION                      Success
MCOSTANDARD                             Success
SHAREPOINTWAC                           Success
SHAREPOINTENTERPRISE                    Success
EXCHANGE_S_ENTERPRISE                   Success

We will now assign an Office 365 license with only the Exchange Online service plan selected. Since we can only assign a plan and all service plans disabled, we first create a object reference that holds all disabled service plans. After that, we assign the license to the service account.

PS C:\> $O365Licences = New-MsolLicenseOptions -AccountSkuId Eveoh:ENTERPRISEPACK -DisabledPlans INTUNE_O365, YAMMER_ENTERPRISE, RMS_S_ENTERPRISE, OFFICESUBSCRIPTION, MCOSTANDARD, SHAREPOINTWAC, SHAREPOINTENTERPRISE
PS C:\> Set-MsolUserLicense -UserPrincipalName "sa-mytt-exch@eveoh.onmicrosoft.com" -AddLicenses "Eveoh:ENTERPRISEPACK" -LicenseOptions $O365Licences

Creating a mail-enabled universal security group

It is recommended to create a mail-enabled universal security group containing the previously created service account. Microsoft throttles the number of requests allowed to Exchange Web Services on a per account basis. By using multiple service accounts, we are able to increase the number of requests to EWS. In the next step, we will delegate calendar permissions to the security group, instead of delegating permissions to the separate service accounts.

On-premises Exchange

Using Active Directory Users and Computers

Add a new group in the OU where you would like to place the security group:

Add the service account to the security group:

Using Powershell

Office 365

Using the Azure Management Portal

Visit the Microsoft Azure Management Portal at https://portal.azure.com, using the credential of your Microsoft tenant that has the subscription to Office 365 you wish to use.
Click "Browse all" to browse all resources.
Click "Activity Directory". You will now be redirected to the classic Azure Management Portal.
Click the Active Directory you would like to manage.
Click "Groups" in the top menu bar.
Click "Add group" in the bottom bar.
Enter a name for the group, e.g. 'Service Accounts MyTimetable Exchange'.
Click the newly created security group.
Click "Add members" in the bottom bar.
Add the service account you have just created.

Using Powershell

Create a new mail-enabled universal security group using the New-DistributionGroup cmdlet. Replace the parameters to match your situation and preferences:

PS C:\> New-DistributionGroup -Name "Service Accounts MyTimetable Exchange" -Type Security -PrimarySmtpAddress "sa-mytt-exch-secgroup@eveoh.onmicrosoft.com" -DisplayName "MyTimetable" -MemberDepartRestriction Closed -MemberJoinRestriction Closed
Name                          DisplayName                   GroupType                     PrimarySmtpAddress
----                          -----------                   ---------                     ------------------
Service Accounts MyTimetab... MyTimetable                   Universal, SecurityEnabled    sa-mytt-exch-secgroup@eveo...

As an optional step, you can hide the security group from the global address list and only accept messages from an administrator account.

PS C:\> Set-DistributionGroup -Identity "sa-mytt-exch-secgroup@eveoh.onmicrosoft.com" -HiddenFromAddressListsEnabled $true -AcceptMessagesOnlyFrom admin@eveoh.onmicrosoft.com

Finally, add the service account to the security group:

PS C:\> Add-DistributionGroupMember -Identity "sa-mytt-exch-secgroup@eveoh.onmicrosoft.com" -Member "sa-mytt-exch@eveoh.onmicrosoft.com"

Delegating calendar permissions to the security group

Finally, we need to give the security group containing the service account(s) delegated calendar permissions on the mailboxes of the users. We assume that all users that are allowed to use the calendar integration are member of a security group.

XXXXXX

Office 365

We are going to connect to Office 365 using Powershell. For this, we have to set up a remote Powershell session. First, we need to check if we are allowed to do so:

Check the current script execution policy

PS C:\> Get-ExecutionPolicy
Restricted

If we are not allowed to execute remote signed scripts, we have to change the execution policy. It might be required for Powershell to be started as Administrator.

PS C:\> Set-ExecutionPolicy RemoteSigned
Execution Policy Change
The execution policy helps protect you from scripts that you do not trust. Changing the execution policy might expose you to the security risks described in the about_Execution_Policies help topic at http://go.microsoft.com/fwlink/?LinkID=135170. Do you want to change the execution policy?
[Y] Yes  [N] No  [S] Suspend  [?] Help (default is "Y"): Y

Now we are able to start a remote Powershell session to Office 365:

Connect to Office 365 using your tenant admin account and import the Powershell session:

PS C:\> $O365Cred = Get-Credential
PS C:\> $O365Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://ps.outlook.com/powershell -Credential $O365Cred -Authentication Basic -AllowRedirection
WARNING: Your connection has been redirected to the following URI:
"https://ps.outlook.com/PowerShell-LiveID?PSVersion=4.0 "
PS C:\> Import-PSSession $O365Session -AllowClobber
WARNING: The names of some imported commands from the module 'tmp_eiaj1j0m.dcw' include unapproved verbs that might
make them less discoverable. To find the commands with unapproved verbs, run the Import-Module command again with the
Verbose parameter. For a list of approved verbs, type Get-Verb.
ModuleType Version    Name                                ExportedCommands
---------- -------    ----                                ----------------
Script     1.0        tmp_eiaj1j0m.dcw                    {Add-AvailabilityAddressSpace, Add-DistributionGroupMember...

First, select all accounts to set the delegation permissions on. We assume that these accounts are grouped in a security group. In the following example, all users are in the security group "Staff". First, get the security group ObjectId

Get all mailboxes

PS C:\> Get-MsolGroup | Where-Object {$_.DisplayName -eq "Staff"}
ObjectId                               DisplayName                GroupType                  Description
--------                               -----------                ---------                  -----------
64731c32-f1df-4b92-8dbe-1809c23ff85b   Staff                      Security

Then select all members of the security group and get their mailboxes:

Get mailboxes by OU

PS C:\> $mailboxes = Get-MsolGroupMember -GroupObjectId 64731c32-f1df-4b92-8dbe-1809c23ff85b | Get-MsolUser | ForEach-Object {Get-Mailbox -Identity $_.UserPrincipalName}

Finally, allow Editor rights for the service account security group to all selected mailboxes:

Exchange on-premises

TODO

Configuring an Exchange service account

Table of Contents

Office 365 / Azure AD prerequisites

Global steps

Creating a service account

On-premises Active Directory

Using Active Directory Users and Computers

Using Powershell

Azure AD

Using the Azure Management Portal

Using Powershell

Assigning an Exchange Online license (Office 365 only)

Using the Office 365 Admin portal

Using Powershell

Creating a mail-enabled universal security group

On-premises Exchange

Using Active Directory Users and Computers

Using Powershell

Office 365

Using the Azure Management Portal

Using Powershell

Delegating calendar permissions to the security group

Office 365

Exchange on-premises