If you want to send out e-mail messages using an e-mail address with your personal domain, you have to make sure that the company will give you access to their SMTP server. The latter is the software system which permits e-mails to be transmitted. SMTP is an acronym for Simple Mail Transfer Protocol and it deals with all outbound email messages from applications, webmail and contact forms. Whenever a message is sent out, the SMTP server confirms with the DNS servers globally where the emails for the receiving domain name are handled and as soon as it obtains this info, it connects to the remote POP/IMAP server to see if the recipient mail box is out there. In case it does, the SMTP server delivers the email body and so the receiving server delivers it to the mailbox where the recipient can open it up and see it. Without having a SMTP server on your end, you will not be able to mail out e-mails at all.