Why Can't I Send Email from my HSR Email Account?

You can, however in order to prevent unauthorized use of our email service we require that you authenticate in order to send email (SMTP) through our mailservers. Many email clients have a checkbox that enables you to use the same login information for SMTP as for checking your email (IMAP or POP). When you try to send email without authenticating, Qmail will usually give you a error like this: 553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1).