Using a domain name hosted by a third-party to send mail across the BT mail servers is known as mail relay.

You do not need mail relay if your domain name has been ordered through BT Business or if you are transferring from another provider

Open mail relay involving unregistered domain names is not permitted by BT. The security policy requires you to register all your domain names before they can be associated with your account.

To set up mail relay please contact us on 0845 600 7020 or fax us on 01382 201594 and request to have mail relay set up for you. Once your request has been received, our agents will verify that you are the rightful owner of the domain name before activating mail relay on your account.

Note: If the domain name is registered in a different name from your BT Business primary account name you need to send us proof that you are entitled to use it. Scan one of the below documents and email the document to us via

  •  a copy of the domain name registration certificate
  • a copy of the invoice from the domain name registrar
  • permission from the domain name owner provided on company headed paper.

Once you have had mail relay activated, please see  How can I configure my email client when using third-party hosted domain name? for special instructions on email configuration.

Important information

BT can only relay domain names that are owned by your organization. Other ISP domains (for example, cannot be relayed.

The following domain extensions are permitted: .eu .com
.net .org
.name .ws .cc
.tv .edu .mil .biz .aero
.coop .museum .pro .info .mobi

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