If you need to send out emails through an email address with your personal domain name, you have to make sure that the company will give you usage of their SMTP server. The latter is the software system which allows email messages to be sent. SMTP is an abbreviation for Simple Mail Transfer Protocol and it addresses all outbound e-mails from apps, webmail and contact forms. Every time a message is sent out, the SMTP server confirms with the DNS servers around the world where the e-mails for the receiving domain are managed and when it obtains this information, it connects into the remote POP/IMAP server to check if the recipient mail box is available. If it does, the SMTP server directs the e-mail body while the receiving server delivers it to the mail box in which the recipient can open it and see it. Without having a SMTP server on your end, you will not be capable to send out messages at all.