In order for you to send out email messages using an email address with your own domain, you have to make sure that the company will provide you with usage of their SMTP server. The aforementioned is the software which enables e-mail messages to be sent. SMTP is an acronym for Simple Mail Transfer Protocol and it handles all outbound emails from apps, webmail and contact forms. When a message is sent, the SMTP server checks with all of the DNS servers worldwide where the emails for the receiving domain are taken care of and once it acquires this information, it creates a connection to the remote POP/IMAP server to see if the recipient mailbox is out there. If it does, the SMTP server directs the message body and so the receiving server sends it to the mailbox where the recipient can open it and read it. Without an SMTP server on your end, you will not be capable to send messages at all.