553 sorry, that domain isn’t in my list of allowed rcpthosts

[crayon-6512b14e3ba22482020359/] The error is basically in Outlook, and requires you to check the option on "My Server requires Authentication" Open outlook >> Tools >> Accounts Click on mail account, and click on Properties There click on Server tab, and you will see option "My Server requires Authentication", click that check box. … [Read more...]