If you wish to send out email messages through an e-mail address with your very own domain name, you have to make sure that the company will give you access to their SMTP server. The latter is the software which enables email messages to be sent out. SMTP is an acronym for Simple Mail Transfer Protocol and it addresses all outgoing email messages from apps, webmail and contact web forms. When a message is sent, the SMTP server checks with the DNS servers globally where the emails for the receiving domain name are taken care of and once it acquires this data, it creates a connection into the remote POP/IMAP server to check if the recipient mailbox is out there. In case it does, the SMTP server directs the e-mail body and so the receiving server delivers it to the mail box where the recipient can open it and see it. With no SMTP server on your server, you won't be capable to send out messages in any way.