Tag Archives: alias email address

Exchange Online: Adding a secondary e-mail domain to all users

I thought that I would share with you a simple script that will add an email domain to your users. This script is handy if you for example would like to add contoso.info to your already existing contoso.com environment. If you are using the email address aaron@contoso.com you want the script to automatically add aaron@contoso.info.

Please note that the domain name that you are adding first has to be added and verified in your Office 365 tenant.

DirSync version (modifying Active Directory using ADSI):

$activeDomain = New-Object DirectoryServices.DirectoryEntry
$domain = $activeDomain.distinguishedName
$searcher = [System.DirectoryServices.DirectorySearcher]"[adsi]LDAP://$domain"
$searcher.filter = '(proxyaddresses=*@contoso.com*)'
$result = $searcher.findall()
$users = $result.Path

$users | ForEach-Object {
    $user = [adsi]"$_"
    $proxyaddresses = $user.proxyaddresses.Value | Where-Object { $_ -like 'smtp:*@contoso.com' }
    foreach ($proxyaddress in $proxyaddresses) {
        $newaddress = ($proxyaddress.split ':')[1] -replace '@contoso.com', '@contoso.info'

Cloud version:

$cred = Get-Credential -Message 'Please enter your Office 365 admin crendentials'
$O365 = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri 'https://outlook.office365.com/powershell-liveid/' -Credential $cred -Authentication Basic -AllowRedirection 
$importcmd = Import-PSSession $O365 -CommandName @('Get-Mailbox','Set-Mailbox') -AllowClobber

Get-Mailbox -ResultSize Unlimited -Filter { EmailAddresses -like '*@contoso.com' } | Select-Object Identity,EmailAddresses | ForEach-Object {
    $proxyaddresses = $_.EmailAddresses | Where-Object { $_ -like 'smtp:*@contoso.com' }
    foreach ($proxyaddress in $proxyaddresses) {
        $newaddress = ($proxyaddress -split ':')[1] -replace '@contoso.com','@contoso.info'
        Set-Mailbox -Identity $_.Identity -EmailAddresses @{Add="smtp:$newaddress"}    

/ Andreas


Mail flow rules for alias email addresses in Exchange Online

Stumbled upon an ‘issue/feature’ with mail flow rules (transport rules) that I’ve encountered before a couple of days ago and thought it was a good idea sharing.
It’s always good to get a reminder of things from time to time, even if it might be a bit obvious 🙂
The ‘issue’ do of course apply to Exchange On premise environments as well.

The user Kalle Kula have three email addresses as following:
SMTP:kalle.kula@corp.365lab.net (primary)

If an email is sent to the address kalle.kula@spam.365lab.net (one of the alias email address for the user), we want to append a disclamer that states “This email was sent to the domain spam.365lab.net”

How to do it:
1. In Exchange Admin Center, under mail flow -> rules, create a new dislaimer rule.
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2. To be able to do more granular selection and actions, click “More Options” in the bottom left corner.

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3. Then create your rule with the following options.

The logical thing here would have been to apply the rule if the recipient address matches my particular address, but that does only work for primary email addresses. So therefore we need to apply it on the header “To” and match the text pattern kalle.kula@spam.365lab.net (the alias address)

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Add your disclaimer and set fall back action.
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The only thing you need to do now for the policy to be applied on future emails is to choose mode: Enforce, save it and you’re done!

If you want to check whether a rule has been used or not, you can use EAC as well.
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PowerShell version:
To do the same as above with PowerShell, you can use the following PowerShell lines:

#Connect to Exchange Online with PowerShell
$cred = Get-Credential
$O365 = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://ps.outlook.com/powershell -Credential $cred -Authentication Basic -AllowRedirection 
$importcmd = Import-PSSession $O365 
#Create the Mail Flow rule (transport rule)
New-TransportRule -Name "Disclaimer - spam.365lab.net" `
                   -HeaderMatchesPatterns {kalle.kula@spam.365lab.net} `
                   -HeaderMatchesMessageHeader To `
                   -ApplyHtmlDisclaimerText "This email was sent to the domain spam.365lab.net" `
                   -ApplyHtmlDisclaimerLocation Append `
                   -ApplyHtmlDisclaimerFallbackAction Wrap `
                   -Mode Enforce 

Further documentation on mail flow rules (transport rules) you find on http://technet.microsoft.com/en-us/library/dd351127(v=exchg.150).aspx.