If you wish to send out e-mails through an e-mail address with your own domain name, you have to make sure that the company will provide you with usage of their SMTP server. The latter is the software system which permits e-mails to be sent out. SMTP is an acronym for Simple Mail Transfer Protocol and it handles all outbound email messages from programs, webmail and contact web forms. Every time a message is sent out, the SMTP server confirms with all of the DNS servers throughout the world where the e-mails for the receiving domain are managed and once it gets this information, it will connect to the remote POP/IMAP server to find out if the recipient mail box is available. In case it does, the SMTP server directs the message body and then the receiving server sends it to the mailbox where the recipient can open it up and see it. Without an SMTP server on your server, you won't be allowed to mail out e-mails at all.