In some companies different departments or branch offices require different primary SMTP addresses.  You can configure these for users with Email Address Policies.  In this example the company wants all users to have an @company.com address, but each branch office’s users have a primary email address representing that branch.

First we must make sure each of the domains is included as an Accepted Domain, using the New-AcceptedDomain cmdlet.

[PS] C:\>New-AcceptedDomain -Name 'Sydney' -DomainName 'sydney.company.com'

Name                           DomainName                     DomainTy Default
                                                              pe
----                           ----------                     -------- -------
Sydney                         sydney.company.com             Autho... False

[PS] C:\>New-AcceptedDomain -Name 'Brisbane' -DomainName 'brisbane.company.com'
-DomainType Authoritative

Name                           DomainName                     DomainTy Default
                                                              pe
----                           ----------                     -------- -------
Brisbane                       brisbane.company.com           Autho... False

[PS] C:\>New-AcceptedDomain -Name 'Melbourne' -DomainName 'melbourne.company.com
' -DomainType Authoritative

Name                           DomainName                     DomainTy Default
                                                              pe
----                           ----------                     -------- -------
Melbourne                      melbourne.company.com          Autho... False

[PS] C:\>New-AcceptedDomain 'Company.com' -DomainName 'company.com' -DomainType
Authoritative

Name                           DomainName                     DomainTy Default
                                                              pe
----                           ----------                     -------- -------
Company.com                    company.com                    Autho... False

Then we can configure the Email Address Policies using the New-EmailAddressPolicy cmdlet.  In this example I am using the “Office” user attribute to filter recipients.

[PS] C:\>New-EmailAddressPolicy -Name 'Sydney' -RecipientFilter {(Office -eq 'Sy
dney')} -EnabledEmailAddressTemplates 'SMTP:%g.%s@sydney.company.com','smtp:%g.%
s@company.com'

Name                       Priority                   RecipientFilter
----                       --------                   ---------------
Sydney                     1                          Office -eq 'Sydney'

[PS] C:\>New-EmailAddressPolicy -Name 'Brisbane' -RecipientFilter {(Office -eq '
Brisbane')} -EnabledEmailAddressTemplates 'SMTP:%g.%s@brisbane.company.com','smt
p:%g.%s@company.com'

Name                       Priority                   RecipientFilter
----                       --------                   ---------------
Brisbane                   2                          Office -eq 'Brisbane'

[PS] C:\>New-EmailAddressPolicy -Name 'Melbourne' -RecipientFilter {(Office -eq
'Melbourne')} -EnabledEmailAddressTemplates 'SMTP:%g.%s@melbourne.company.com','
smtp:%g.%s@company.com'

Name                       Priority                   RecipientFilter
----                       --------                   ---------------
Melbourne                  3                          Office -eq 'Melbourne'

Here is the result for a recipient who matches the filter for the Sydney policy.

[PS] C:\>Get-Recipient 'Peter Grover' | fl Office,Emailaddresses

Office         : Sydney
EmailAddresses : {smtp:Peter.Grover@company.com, SMTP:Peter.Grover@sydney.company.com}