About mailboxes, addresses and aliases

Normally a mailbox only has one e-mail address. However, nowadays, several e-mail providers allow you to set multiple addresses on just one mailbox. In the corporate world, it is also not uncommon to have addresses from ex-employees or special projects assigned to your (Exchange) mailbox.

This guide describes the definitions and affects of aliases on Outlook.

So what are aliases?

Aliases are nothing more than different ways to mail to a certain mailbox. Just like a single person can be reached on more than one phone number, a single mailbox can be reached via different email addresses.

In most cases your ISP will give you one mailbox with one address they choose for you (often this is an abbreviation of the name you are registered with for their services or your username). They probably will also give you the opportunity to add 3 or 5 address you choose to the mailbox. This can be any name as long it has not been reserved already.

Within a company, you usually cannot pick your own address(es) for your mailbox but it (they) will be generated according to your company’s standards.

Why would I need an alias?

An alias can be quite handy for sorting your incoming mail or just so that your e-mail address looks better to the one you give your address to. Think about the following situations;

  • You got one mailbox from your ISP with a default address of your username e.g. jsmith123@ISP.com
  • For your friends and family to contact you, you can have your full name e.g. john_smith@ISP.com
  • For professional use of your address you would like to have an address that just looks better e.g. j.smith@ISP.com
  • For newsletter signups, you can append “-newsletters” to your address e.g.

The messages sent to the aliases still end up in your mailbox just like they were sent to the original address. However, in Outlook you can now set rules on how the emails behave (like sorting them into different folders) when sent to a specific alias. You could compare this with how you can decide not to pick up your business phone after 17.00 but still answer your cell phone ;-).

Can I change my default alias I send out with?

Go to your account properties and change the e-mail address to the alias you like. Yes, it is that simple! Leave your login information as is, even when this is formatted like your main email address.

You can change your outgoing alias address simply by changing the address in your account settings.
E-mail address configuration for POP3 and IMAP accounts.

Can I choose which alias to send out with?

There are various methods to overcome this depending on your needs, Outlook version and mail account type.

Method 1: Configure an additional POP3 account

You can easily overcome this problem by setting up a (second) POP3 account alongside your original POP3/IMAP/Exchange or Hotmail account but with one of your aliases as the address.

If your current mail account type is an IMAP or Exchange account, contact your ISP or mail administrator if your mailbox is also accessible via POP3. For an overview of POP3 settings for popular free accounts see; Configure Hotmail, Outlook.com, Gmail, Yahoo or AOL.

Make sure you set the Send/Receive settings for the alias account to not to receive mail to prevent duplicates. For more information about how to configure this see the guide Duplicate E-mails – Multiple Accounts.

Now when you want to send a message with an alias, you can press the Accounts button next to the Send button to select the alias account. In Outlook 2010 and Outlook 2013, you can click on the From button to select your outgoing account.

Account selection in Outlook 2007 Account selection in Outlook 2010
Account selection in Outlook 2007. Account selection in Outlook 2010/2013.

Method 2: From field and “sent on behalf of”

Another way to go would be to set the From field, when composing a new message, with the alias you want to send with. To enable the From field for your version of Outlook see; Enabling BCC and From fields.

You can now type the address that you want to send out with. In Outlook 2010 you must select “Other E-mail Address…”.

The downside of this method is that you will send the message “on behalf of” so it will look like this; (default alias) on behalf of (alias). This is because this option is normally used in Exchange environments where people can allow others to send out a message out of his/her name; very handy for secretaries who handle the mails for his/her boss.

By manually setting an address in the From field, you'll be sending "On behalf of". Replies will be sent to the alias address.
By manually setting an address in the From field, you’ll be sending
“On behalf of”. Replies will be sent to the alias address.

Changing the main alias on a Hotmail or Outlook.com account

When you changed your default alias for a Hotmail or Outlook.com account via the web interface, you’ll need to remove the account in Outlook and then re-add it again with the new alias.

When adding your account in Outlook 2003, 2007 or 2010, choose to manually configure your account and select as the account type “Other”. Here, select the Outlook Hotmail Connector. If you do not have it installed yet, you can download it here.

When you use Outlook 2013, you must select the EAS account type and use m.outlook.com or m.hotmail.com as the server name.

To add an Outlook.com alias to your existing Hotmail account, logon to the Outlook.com website with your current address and press the white gear icon in the top right corner (next to your account picture and name). From the menu that pops-up, choose: More mail settings. In the “Managing your account” section, click on “Create a Outlook alias”.

Aliases on Exchange mailboxes

If you have an Exchange account with multiple addresses assigned to it, the above methods will not work. The first method often doesn’t work because configuring your Exchange account as an additional POP3 account usually isn’t allowed. The second method won’t work since when you type the address of the alias, Exchange automatically resolves the address to your mailbox and continues to send out with what is configured your default mailbox address on the Exchange server.

To overcome this, there are 2 methods but both require assistance from your Exchange administrator.

Method 1: Configure an Active Directory Distribution Group with your alias

This method is only really workable when there are only a small amount of people in your organization who need to send out via specific aliases. The reason for this is that it requires quite a bit of additional configuration on the administrator side and it also breaks some principles of centralized administration (Method 2 offers a more integrated solution).

Instructions for the Exchange administrator;

  1. Create a mail enabled Active Directory Distribution Group with the name of the user you want to create an email alias for. You can do this via the Exchange Management Console (so not in Outlook!).
  2. Set the primary reply email address of that Distribution Group to the alias for the user.
  3. Add the user this alias is for as a member to the Distribution Group.
  4. Set “Sent As” permissions on the Distribution Group for the user who this alias is for via Active Directory Users and Computers or via PowerShell;
    • Active Directory Users and Computers
      Set your view to “Advanced Features” (via the View menu), open the Contact and select the Security tab. Now add the user who this alias should belong to and select the “Send As” permission.
    • PowerShell (AKA; Exchange Management Shell or EMS);
      Get-Group -Identity "Group Name" | Add-ADPermission -user "Domain\Username" -ExtendedRights "Send As"

In Exchange 2007/2010/2013 or Office 365, you can also do this by creating a mail enabled Active Directory Contact with the alias address as its “External E-mail Address” and create an Exchange Transport Rule to deliver it to the user’s mailbox. To set the “Send As” permissions on the Contact for the owner of the alias, you can use Active Directory Users and Computers or the following PowerShell command;
Get-Contact -Identity "Contact Name" | Add-ADPermission -user "Domain\Username" -ExtendedRights "Send As"

Setting Send As permissions on an object in Active Directory Users and Computers (click on image to enlarge).
Setting Send As permissions on an object in
Active Directory Users and Computers (click on image to enlarge).

As you’ve changed the group membership of a user, the user must log off and then log on again for changes to take affect. Then, after the Offline Address Book has been regenerated on the Exchange server and been updated on the client, the user should be able to see this newly created Distribution Group in the Global Address List (GAL). Now the user can select this Distribution List and set it as the From field without the address being resolved to the primary address of his/her mailbox and without getting the “sent on behalf of” part on the receiver’s end.

Let the user add this Distribution Group or Contact to his/her Contacts folder in Outlook so that you can hide it in the GAL.

Method 2: Use the ChooseFrom and SmartReply add-in

To deal with the alias dilemma a bit more structured and centralized, you can install a Transport Agent on the Exchange server and deploy an Outlook add-in to the users who need to send or sort mail from one of their configured aliases.

The combination of these tools from IvaSoft offer the following benefits;

  • It allows the Exchange administrator to continue to configure aliases directly on the user object/mailbox without the need to create additional AD Contacts for each alias.
  • It allows the user to select an alias as if it was a separate account and also allows the user to sort incoming mail based on the alias specified by the external sender.

Author’s note:
I usually try to find various alternatives when suggesting a tool or add-in, but in this case I just couldn’t find any and these software solutions seem truly unique. While your initial impression of the IvaSoft website might not be so great, the tools themselves are and so is the technical support (which for me ended up being an issue with an Exchange 2007 Update Rollup for which now is a warning on the site).

ChooseFrom – Exchange Transport Agent

The ChooseFrom application from IvaSoft is a custom Transport Agent fro Exchange which allows your users to send out messages with one of their configured alias addresses.

To do this, they can either specify this alias as the Reply-To address when composing a message or select it as a sending account when used in conjunction with the SmartReply Outlook add-in. ChooseFrom will then restamp the From address of the message with the address specified in the Reply-To field or by SmartReply.

More information: ChooseFrom for Exchange 2000/2003
More information: ChooseFrom for Exchange 2007/2010
More information: ChooseFrom for Exchange 2013

ChooseFrom is easy to install and doesn’t require a reboot of Exchange.

SmartReply – Outlook Add-in

SmartReply from IvaSoft is an Outlook add-in which allows you to see all your Exchange mailbox aliases as separate sending accounts. This enables you to send out messages with those aliases instead of only your primary address set by your Exchange administrator.

In addition, you can see which alias the message had been sent to (and sort your mail accordingly), automatically reply with that alias and specify a different signature for each.

More information: SmartReply for Outlook 2003/2007
More information: SmartReply for Outlook 2010
More information: SmartReply for Outlook 2013

SmartReply detects your Exchange aliases and allows you to choose from them like if they were separate mail accounts.
SmartReply detects your Exchange aliases and allows you to choose from
them like if they were separate mail accounts.

ChooseFromOWA – OWA extension

The ChooseFromOWA application from IvaSoft allows your OWA users to send out messages with one of their configured alias addresses. It works as a Transport Agent and leaves your OWA files untouched.

After configuring, OWA users can select from one of their aliases via the “Message Classification” option in OWA.

More information: ChooseFromOWA for Exchange 2007/2010