Domain Alias
is a feature of Plesk Control Panel, by which you can share same Server
Space (Web Site and Mail) for your multiple Domain(s). The domains that
are aliased will point to the main hosted domain and will serve the
same website contents.
In case of Domain aliasing for mails any mail sent to the aliased
domain name will be forwarded to the mail domain containing the
physical mail boxes.E.g. if there is a Mail ID in your domain called
user1@yourdomain.com and you created a Domain Alias for domain2.net
then the mail user user1@yourdomain.com will automatically be mapped
to user1@domain2.net so that mail addressed to user1@domain2.net will
be delivered to the mail box of user1@yourdomain.com.
For using Outlook, webmail you need to use the access details for your
primary domain i.e. yourdomain.com. The mails for alias domain will be delivered to the Mailbox of the Primary domain User.
Login to your Plesk Control Panel.
For creating Domain Alias click on on Domain Aliases in Website .


Now click on Add New Domain Alias.


Type the Domain name to alias and select the required Services and click OK to save the changes.

Your domain alias has been created.You need to wait for few hours for Global DNS transition.

Logout after you have finished.