If you wish to send out e-mails through an e-mail address with your own domain, you have to make sure that the company will give you usage of their SMTP server. The latter is the software system which allows emails to be sent. SMTP is an acronym for Simple Mail Transfer Protocol and it manages all outgoing email messages from applications, webmail and contact forms. Whenever a message is sent, the SMTP server confirms with the DNS servers throughout the world where the e-mails for the receiving domain are handled and when it gets this data, it connects into the remote POP/IMAP server to find out if the recipient mail box is available. In case it does, the SMTP server directs the email body while the receiving server delivers it to the mailbox where the recipient can open it up and read it. With no SMTP server on your end, you won't be allowed to send emails in any way.