In order for you to send out e-mail messages through an email address with your own domain, make sure that the company will provide you with usage of their SMTP server. The aforementioned is the software that enables emails to be sent out. SMTP is an acronym for Simple Mail Transfer Protocol and it manages all outgoing e-mails from apps, webmail and contact web forms. Every time a message is sent out, the SMTP server confirms 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 will connect to the remote POP/IMAP server to see if the recipient mailbox is available. When it does, the SMTP server directs the message body while the receiving server sends it to the mail box where the recipient can open it and read it. With no SMTP server on your end, you won't be allowed to send messages at all.