1. Open Mac Mail
2. Click on the ‘Mail’ menu in the upper left, then select ‘Preferences’
3. Click on the ‘Accounts’ icon along the top
4. You will be in ‘Account Information.’ If you have multiple accounts listed on the left side, click to choose the one associated with Atlas Hosting, then click on the ‘Server Settings’ tab on the right.
5. In the ‘Server Settings’ tab, under both Incoming and Outgoing server change your ‘User name’ by appending your domain name to the end of the existing value as seen below.
In the example below the domain used is atlashosting.com, but you should use your own domain name.
6. Once done, click on the ‘General’ tab and you should be prompted to save settings. Do so.
7. That’s all! You should be able to continue using mail as normal.