Email Firewalls

Managing incoming messages to prevent spam, viruses, and phishing attacks can be a lot of work. That’s why large corporations usually install “email firewalls”, or hire 3rd party vendors (like “Barracuda Firewall” or “Postini”) to handle their incoming email.

Email firewalls often use a combination of Bayesian-style/adaptive filters, community reporting, blacklists, and a little bit of proprietary “magic pixie dust” to keep spam out of the company. Most of the time, when you can’t deliver email to a large company, it’s their firewall.

Firewalls tend to ask questions like, “Is this sender new to me? Why is he sending copies of the same email to a bunch of people in our company? Spammers do that stuff. Can I really trust this sender?”

Spam firewalls are usually a problem when you are sending campaigns to a big client for the first time. You are “new” to firewall and so you experience some deliverability troubles. They’ll eventually “learn” to let you through.

To solve the problem in a quicker way, you can ask the IT people in charge of the firewall to “whitelist” your IP addresses (or the IP address of your email service provider).


Table of contents | Page list for this chapter | Next page


Spam Testing for Marketers

GlockApps Spam Testing

Reach the inbox every time.

Improve your delivery rates

Improve your deliverability by scanning your emails through all the major spam filters before you send.

Get actionable tips

Receive a spam score as well as actionable tips for improving your delivery rates for every email send.

Increase your revenue

Improve your overall email performance by ensuring more emails are getting through to your subscribers.

All content copyright © G-Lock Software. All rights reserved. No part of this book or site may be reproduced or redistributed in any form or by any electronic or mechanical means, including information storage and retrieval systems, without permission in writing from G-Lock Software, except by a reviewer who may quote brief passages in a review.