How to block senders based on email header in GravityZone
GravityZone Security for Exchange comes with highly configurable settings, securing the Microsoft Exchange Servers against threats such as malware, spam and phishing.
With Exchange Protection module installed on your mail server, you can also filter emails containing attachments or content considered dangerous according to your company's security policies.
For known email senders, you can prevent unnecessary server resource consumption, by including them into lists for untrusted senders, configurable in GravityZone console. Thus, the email server will always reject emails coming from those senders.
In some situations, even though some senders are blocked, you may still receive emails from them. This happens if the emails are originating from addresses different from the ones you have added to the blacklist in policy settings.
To solve this issue:
- Open the email sample (in .eml or .msg format) and go to File > Properties.
- Check the Internet headers section to see from what address the email has been sent.
- Add the email address to the blacklist in GravityZone policy settings.
Also, make sure the Realtime Blackhole List (RBL) is properly configured. For details, refer to this article.