In order for you to send e-mail messages through an email address with your very own domain, make sure that the company will give you usage of their SMTP server. The latter is the software system that enables emails to be sent. SMTP is an abbreviation for Simple Mail Transfer Protocol and it deals with all outgoing email messages from applications, webmail and contact web forms. When a message is sent, the SMTP server confirms with all the DNS servers around the world where the emails for the receiving domain name are taken care of and as soon as it obtains this data, it connects to the remote POP/IMAP server to see if the recipient mailbox exists. If it does, the SMTP server transmits the message body and then the receiving server sends it to the mail box where the recipient can open it up and see it. Without having a SMTP server on your server, you won't be allowed to send emails in any way.