Error 550: Relaying DeniedArticle Id kb15 Published 19 Jul 2012 at 12:24 Last Updated 27 Nov 2013 at 16:01 CalzadaMedia.Common.AppFoundation.WebApp.UI.WebComponent.WebComponentOutputStringBuilder You may receive this error if you try to send e-mail through our servers for a domain unknown or blocked by us. We will only relay mail for known domains and for accounts have authenticated against our mail servers.