You can modify the email settings for a particular domain in the Control Panel or in the MAC
To modify a domain in the Control Panel
1. In the Email section of the Control Panel, click the Email Domains tab.
2. In the Quick filter text box, enter all or part of the domain name for which you want to search, and then click Search.
3. Click the domain you want to edit, and then click the Settings tab.
4. Click Edit in each section to edit the related fields, and then click Save.
For an explanation of the fields in each section, see "Creating a new domain for Email accounts"
To modify a domain in the MAC
1. Log in to the Mail Administration Console (MAC).
For more information, see "What is the MAC?"
2. Navigate to the domain that you want to modify. See “Searching in the Mail Administration Console (MAC)”.
The Domain page opens, displaying the Settings tab. You can click on the tabs at the top of the page to view additional fields.
3. Modify the applicable domain detail fields. For an explanation of these fields, see "Creating a new domain".
4. Click Update.