Using Domain Aliases

Updated Tuesday, October 27, 2020

Introduction

Domain aliases allow linking additional domains onto all addresses of a primary domain. They extend both receiving addresses as well sending identities on primary domains.

This feature can come in handy when operating multiple brands or web properties through one parent company for example. We internally use domain aliases for receiving messages via multiple top level domains.

Configuration

The first step is configuring the domain alias in the Migadu admin panel. The related section is under DNS Configuration > Domain Aliases within the domain you wish to use as your primary domain.

The DNS setup that follows should be familiar from the setup of the primary domain.

Receiving on Domain Aliases

When receiving on a domain alias, the destination address is simply rewritten as the same local part on the primary domain before proceeding with further lookups (aliases, rewrites, mailboxes/identities, catchalls). This means the incoming message should land in the same local part at primary domain.

For example, if primary domain doe.com has a domain alias configured doe.net then john at doe.net becomes first john at doe.com after which it gets looked up on the primary domain.

Note that domain aliases themselves do not have storage as they serve only as pointers to the primary domain.

Sending From Domain Aliases

When sending from a domain alias, the SMTP authentication must still happen with the credentials of the primary domain. The domain alias do not extend the credentials of mailboxes and their linked identities.

To use domain aliases for sending, configure additional sender personas on the aliased domain in your email client serving your primary mailbox. The email client should offer a choice of personas to use when composing messages and automatically preselect them in replies.