1. open manage.liquidweb.com/manage/domains/ and search for the domain you are interest.

2.open the + sign and look for mail.somthing... - >  copy this address for later use.

3.open https://cloudsites.mycpsrvr.com/ , log in  > click on Mailbox >  search for the domain you are interest.

4.Add mailbox > give it a name and pass.

5. in your website or web-config file - set the new SMTP details using smtp mail from stage 2. > user and password.

for example:

smtp server : mail.perform-365.com

user: mail@perform-365.com

pass: #####