Tag Archives: email message

How to Test Your SPAM Filter

Does my Email Filtering Solution Work?

Sometimes as email administrators we need to test if the SPAM filter works and is filtering messages. In order to do this we need to send a test message with content that we are sure is rated as SPAM.

GTUBE – Generic Test for Unsolicited Bulk Email

The GTUBE the “Generic Test for Unsolicited Bulk Email” is a test that can verify if your antispam filter is installed correctly and is detecting incoming spam.
GTUBE works in a similar fashion to the EICAR anti-virus test file.
Insert the following string in any email message and your antispam filter should detect it and filter it accordingly.
Note that this string should be written in one line, without whitespace or line breaks.
Note that this string and can be reproduced freely, without attribution; they are hereby placed in the public domain.

SPF – Sender Policy Framework an Antispam solution

The Email Administrator has to implement SPF filtering on the mail servers and create SPF records for your mail server. SPF is the acronym for Sender Policy Framework and is an open standard specifying a technical method to prevent sender address forgery. SPF protects the envelope sender address giving the opportunity for a mail server to check if an email message is originating from a valid source and not from a forged source.
The technology requires two sides configuration:
(1) The domain owner publishes an SPF record in the domain’s DNS zone.
(2) The receiving server checks the message against the SPF record policy in the DNS zone.
The receiving mail server then can accept or reject the message based on the compliance with the domain’s stated policy. If the message comes from an unknown server, it can be considered a fake.
The SPF will help tremendously against spoofing. Email Spoofing means faking the source of an email message so that it appears as coming from a different source. This will avoid a lot of messages that appear to come from your address but you never sent. More about spoofing on this Wikipedia article: http://en.wikipedia.org/wiki/E-mail_spoofing