In order for you to send out e-mails using an email address with your very own domain name, you have to make sure that the company will provide you with access to their SMTP server. The aforementioned is the software system that enables emails to be transmitted. SMTP is an abbreviation for Simple Mail Transfer Protocol and it handles all outbound e-mails from apps, webmail and contact forms. Every time a message is sent, the SMTP server confirms with all the DNS servers around the world where the e-mails for the receiving domain name are handled and once it obtains this info, it creates a connection to the remote POP/IMAP server to see if the recipient mail box exists. If it does, the SMTP server sends the message body while the receiving server delivers it to the mail box in which the recipient can open it and read it. With no SMTP server on your server, you will not be allowed to send emails at all.