Sender restrictions
Sender restrictions control who is allowed to send mail from your domain.
Sender restrictions are defined by the combination of two separate settings:
- Domains have a Sender Restrictions setting. This controls what restrictions are applied to the domain.
- Mailboxes have a Sender Authorisations setting. This controls the email addresses that a mailbox is authorised to send from.
Domain sender restrictions
To configure Sender Restrictions for your domain, go to Web and Email Hosting in the control panel and click on the Email Settings link for your domain.
The Sender Restrictions setting has three options:
- Unrestricted – this is a legacy option, and we do not recommend using it.
- DKIM restricted – outgoing mail will only be signed using DKIM if it is sent by an authorised sender. If the sender is not authorised, the mail will still be accepted, but it won't be signed.
- Sender restricted – outgoing mail from your domain will only be accepted if the sender is authorised.
You should only enable sender restricted if all legitimate sources of mail from your domain sign messages using DKIM. This includes any third party mailing list services and any other email providers that you may use. This is because, with this setting enabled, our mail servers will prevent other customers from forwarding email from your domain unless it is DKIM signed.
Mailbox sender authorisations
To access the sender authorisations settings for a mailbox:
- Go to Web and Email Hosting.
- Click on Email Addresses for your domain.
- Click on Details for the mailbox.
A mailbox can be authorised to send from:
- Address only – just the mailbox name.
- Domain – any address in the same domain as the mailbox name.
- Account – any address in any domain hosted on the same hosting account.
For example, if you use a mailbox called me@example.com to send mail, and the domains example.com and example.co.uk are hosted on your account, then the settings will have the following effect:
- Address only: you are only authorised to send from me@example.com.
- Domain: you are authorised to send from any address in example.com, such as info@example.com or sales@example.com.
- Account: you are authorised to from addresses in other domains hosted on your hosting account, for example info@example.co.uk.
Note that the effect of being authorised or not depends on the domain sender restriction for the domain, as described above.
Mail sent from your hosting account user
It is also possible to send mail using the sendmail command on your hosting
account. This is typically used by websites that generate emails (such as
contact forms or verification emails), but can also be used by other scripts
running on your hosting account. Mail sent in this way is treated as authorised
to send from any address in any domain on the hosting account.