If you would like to send emails through an email address with your own domain name, you have to make sure that the company will provide you with access to their SMTP server. The latter is the software that permits e-mail messages to be transmitted. SMTP is an acronym for Simple Mail Transfer Protocol and it manages all outbound e-mails from apps, webmail and contact web forms. Every time a message is sent, the SMTP server checks with all of the DNS servers around the world where the e-mails for the receiving domain name are taken care of and as soon as it obtains this data, it creates a connection to the remote POP/IMAP server to find out if the recipient mailbox exists. When it does, the SMTP server delivers the message body and so the receiving server sends it to the mailbox in which the recipient can open it and see it. Without an SMTP server on your end, you won't be capable to send out messages at all.