You can put email delivery for a domain on hold. We will accept email for a domain that's on hold, but we won't try to deliver it to your mailserver. We'll queue it until you release the hold.
Note that we will queue mail regardless of whether you put it on hold or not, in the event that we cannot reach your mailserver.
The proactive step of placing delivery on hold is useful if you want to pause delivery while you upgrade a mailserver, you're making changes to your email accounts list, etc.
You can put email delivery on hold two different ways.
Click on the domain you want to put on hold or click on the Delivery column under Domains. To resume mail delivery, just click on the word Hold and it will change to Deliver.
2. Click on the Hold Delivery tab. Then click Edit, check the box and hit Save. Be sure to go back and uncheck the box and hit Save to resume mail delivery.