Configure Accepted Domain in Exchange 2016

After you install Exchange 2016, you may want to setup accepted domain. By default fully qualified domain name (FQDN) of forest root domain is configured as authoritative accepted SMTP domain. If you want to accept emails for more or different SMTP domain names or relay emails then you need to configure accepted domain in Exchange 2016. If you also have .local internal domain name and want .com or other domain name then this is where you add the domain name.

Configure Accepted Domain in Exchange 2016

To configure accepted domain in Exchange 2016 log on to Exchange Admin Center (EAC). Select mail flow in the features pane. Click accepted domains tab.

Configure Accepted Domain in Exchange 2016

You can see above, domain is the default SMTP domain and it is authoritative. This is because the active directory site has a root domain of You can configure three different types of accepted domains: –

  1. Authoritative: – In authoritative accepted domain, Exchange server hosts mailboxes that have email address that use that domain. For example, MustBeGeek is a company with domain name. If a Exchange server hosts mailboxes with email address containing domain then is considered to be authoritative domain. Many organizations have company.local internal domain which is not routable on the internet so you have to add SMTP domain as accepted domain. In addition, you have to create email address policy to match domain name. Mail exchange (MX) record also needs to point to domain. Exchange organization can be configured with more than one authoritative domain.
  2. Internal Relay: – In internal relay accepted domain, Exchange server of the company hosts some mailboxes and rest are hosted somewhere else. This is useful if you have shared SMTP domain between two organization where some mailboxes reside in one company and some on other. So when you configure internal relay, exchange server will try to find mailbox in existing Exchange network first and if it doesn’t find it will forward to another organization using configured list of send connectors.
  3. External Relay: – In external relay accepted domain, Exchange server of the company accepts emails for non-authoritative domains and forwards them to authoritative mail servers via send connector. If you want your Exchange server to be SMTP server for other organization or companies then you have to configure external relay. Your Exchange server doesn’t host mailboxes but will receive emails from other organization and forward it to external SMTP servers.

To add new authoritative domain click + “Add”.

new accepted domain

Type name to recognize the accepted domain. Type accepted domain name, example Choose authoritative option. Click save.

Configure Accepted Domain in Exchange 2016

Accepted domain is created as shown above. You can now create email address policy to assign email address consisting of new SMTP domain to mailboxes.

In this way you can configure accepted domain in Exchange 2016.

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Bipin is a freelance Network and System Engineer with expertise on Cisco, Juniper, Microsoft, VMware, and other technologies. You can hire him on UpWork . Follow Bipin Giri on Google+. Bipin enjoys writing articles and tutorials related to Network technologies. Some of his certifications are, MCSE:Messaging, JNCIP-SEC, JNCIS-ENT, and others.