Valid From Domain

Information Details

Normally, the reason you have reached this page is because a mail server has sent you a message when it rejected an email from you, or one of your users.

Information for Email and Network Operators

Although email servers can (by RFC) accept connections that have few limitations in what is presented in the MAIL FROM: portion, most email servers and anti-spam tools use this in Spam identification. An email client, or server MUST provide a FULL email address, and the domain portion must be a legitimately formed domain name. Some Anti-Spam technologies will go even farther and check the validity of the domain, ie that it has an A or MX record in DNS, which means that it can be responded to. No email should be sent from an address that cannot be responded to. Most servers have the ability to add a 'defaulthost' or 'default domain' to any user/email that doesn't supply one. Make SURE this isn't still set to some default provided, such as 'localhost' or 'localdomain' and make sure that the domain has a correct DNS entry for A and MX records for that domain.

In order to ensure that messages are not stopped by this check, make sure the MAIL FROM is issued by your server or scripts.

An example would be:

220-mail.receiveingserver.com ESMTP
HELO mail.sendingserver.com
250 mail.receiveingserver.com
MAIL FROM: user@domain.com
-- or --
MAIL FROM: <user@domain.com>
Spammers, bulk mailers, and trojans and bots often do not handle the MAIL FROM: correctly, and this makes spam detection easier, and also helps you identify exactly what server was causing a problem. Many email administrators who buy off the shelf mail server software may not correctly set up the 'defaulthost' or 'defaultdomain' , and instead it may default to just a generic identifier, or not be sent. Ensure that you correctly configure your mail server. eg 'user@localhost' or 'user@non-existantdomain.com'. If you are the one sending the message, and you were blocked with this message, it is most likely that your email client has not been set up correctly. Check your 'Outlook' or 'Thunderbird' settings, and make sure that you are using your full email address properly in all the correct fields for your account.

Information for users. Why was my email blocked?

If your email was blocked, and the link sent you here it is probably your fault. It CAN be the fault of a poorly configured outgoing email server, however it can be caused by other reasons:

Normally, this rule will only block spammers who don't, or can't change the functionality of the tool they are using to send spam, or by pass sending this to avoid detection by some spam softwares.

For help on this you should contact your email administrator.