If you have a Mailbox associated with a domain name on your PhotoBiz account and you decide to change your domain name, you may want to keep your Mailbox active. You can keep your Mailbox active, however there a few items you'll need to confirm when changing the domain name to make sure your email service continues. 

• 1. Domain Registration needs to remain active

• 2. The DNS settings for your domain need to include the PhotoBiz Mailbox MX records
  
  Guide: PhotoBiz Mailbox MX Records & Settings

• 3. Mailbox product needs to remain active on your account

As long as you have all 3 of these set up properly, you won't have any interruption of service if you change the domain on your account to another domain name.