Functionally, aliases are additional mail addresses for a single mailbox. OX App Suite will route all mail for any of those aliases to the same mailbox. 

OX App Suite's native features allow you to choose which alias to use as the FROM address in either the webmail interface or in a desktop or mobile mail client. You can only select email addresses or aliases that already exist in OX App Suite and not other arbitrary addresses for the same domain.

You can create, view, and delete aliases from the list of email addresses on the Product Details page for OX App Suite in the WHMCS Client Area. For more information, see How do I add an alias?.

Aliases are not the same as forwarders, which are supported separately in several different types, including on OX Cloud.