Ok this is my problem. I have a site hosted in Plesk, call it domain.com. However, the MX records for domain.com are NOT set to the plesk server but to other external servers. (Basically there is no need for plesk to handle email for this domain) Now even though email for domain.com is disabled in the control panel and the MX records for domain.com correctly point to the external servers, if I attempt to send email FROM the plesk server to email@example.com, the domain is treated as being local and so is never sent to the correct SMTP server defined by the MX records for the domain. So my question is How do I host a site in plesk but prevent the domain name from being treated as a local domain with regard to email delivery?