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Prolateral offers primary and backup domain (DNS) services, with servers in key geographic locations providing the best service possible.


What is Fake SMTP?


Fake SMTP can have two meanings. Firstly, it can relate to the term Fake MX which is a method of spam email prevention. Secondly it can relate to a pretend (dummy) email server typically used by developers when testing outbound emails and need a “fake” SMTP server to receive those emails.

Fake MX

Fake MX is a tool for combating against spam, but you already have a spam filter, right? Fake MX is an additional tool in the fight against spam.

A typical set up for a company is to have at least two border (edge) email servers that receive external email for your company. On the primary email server, you have the latest and greatest spam filtering and the second email server running as a backup (for redundancy) for those days the primary goes offline. Hopefully the backup email server is running the same spam filter software as well.

However so often is the case the backup email server & software isn’t as up to date as the primary server. This is why the typical spammer will target the backup email server hoping their emails will sneak past any protection and reach their intended target.

Furthermore, which ever server is accepting emails for your domain you are still receiving the mass volumes of spam emails and rejecting them at the border. This is still using up valuable bandwidth on your expensive Internet connection.

This is where Fake MX comes in.

Fake MX is a hosted SMTP server that effectively becomes your third email server sitting at the lowest priority in processing order of mail servers for that domain name. In terms of DNS MX records the higher the MX number the lower the priority.

As we discussed earlier spammers target the lowest priority server thinking they can sneak past. However, this time they reach a fakeMX server.

fakeMX server works by simply telling ALL emails to temporarily go away and try again in a few minutes. Most spammers don’t bother coming back and therefore helps to combat against spam. For some companies this has seen a 40-60% drop in the total volume of emails hitting the primary servers, all of which is spam. Any legitimate email would normally go via the primary email server, but if by chance it does hit the fakeMX server its also told to temporarily go away and come back. When a legitimate email comes back it will try the primary server and be delivered.

Prolateral offers a fakeMX service to end-users and our partner/resellers.


Fake SMTP (also known as a DUMMY SMTP) is a useful testing tool for staging and development. When software developers are creating an application that needs to send emails out, or if you’re in the process of setting up a demo of something and that solution needs to send emails out you don’t want emails to actually go out to real people.

This is where the fake SMTP service comes in. You can setup your application or demo to send emails out to the fake SMTP server. That way you can test your application and see the email send out before going live with a production application/service.


You decide you want to add an eCommerce solution to your website. You install the software and configure it but you want to test the cart process and also the invoice email that is sent to the customer. So, you set up the SMTP server settings in the eCommerce solution to use a fake SMTP server. Now you can test the process and see the email the recipient would receive.

Sample of Fake SMTP Tools & Services

There are many services out there that offer fake SMTP below are just a few. You will find many more from a web search some with additional features, some enabled for bulk email testing. Only you will know the best solution for your testing environment.


This is a FREE JAVA based application that runs on the desktop.


This is an online service with various levels of subscriptions, including a FREE package for personal use.


MailHog runs on Unix and Windows, with Docker instances available. It is a fake SMTP server with a web based GUI to see the received messages.

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The Origin of this information may be internal or external to Prolateral Consulting Ltd. Prolateral makes all reasonable efforts to verify this information. However, the information provided in this document is for your information only. Prolateral makes no explicit or implied claims to the validity of this information. Any trademarks referenced in this document are the property of their respective owners.