SMTP Error - Important facts

For administrators:

Important facts to remember when delivering mails to Tourismus Salzburg GmbH
Tourismus Salzburg IT uses spam protection for its mailboxes.

If your system is misconfigured mails will be rejected permanently without reaching end user.
(SMTP: 5XX permanent error will be sent to your mailserver)
Please ensure and configure you mailserver according to international norms:

E-Mails must comply to the standards described in RFC 2822.

E-mails should not be delivered from within dialup IP ranges with periodically changing IP adresses

The delivering server must have a reverse DNS entry with a fully qualified domain name.

A complete and plausible HELO/EHLO as described in RFC 2821 must be sent.

We check the sending server for SPF compliance if the user hasn't disabled this setting.
The addresses of forwarded e-mail therefore MUST be rewritten using SRS standards.

The communicating server must not be an open proxy and must be protected against unauthorized access.

In case of any error we ALWAYS provide an error message in the SMTP dialog which cleary indicates the source of the problem.

Please check you server logs if you experience problems. In case of reoccuring errors it is useful to identify the very first instance when the error occured.

We check several well established RBLs.
Should one of them match our SMTP answer will tell you which, why and what to do.