Adding a Gmail filter to whitelist 33mail emails

Unfortunately Gmails spam filters are not always 100% accurate and valid emails from services such as 33mail can get mistakenly marked as spam.

A useful feature in GMail is the ability to create filters that prevent misclassification of valid emails.

In this guide, we walk through the process of setting up a filter in Gmail to ensure emails from 33mail are never sent to the spam folder.

Step 1: Open Gmail and Access Settings

  1. Open your web browser and log in to your Gmail account.
  2. In the top right corner, click on the gear icon to open the settings menu.
  3. Select “See all settings” from the dropdown menu.

Step 2: Navigate to the Filters and Blocked Addresses Tab

  1. In the Settings menu, click on the “Filters and Blocked Addresses” tab.
  2. Scroll down and click on the “Create a new filter” link.

Step 3: Set Up Your Filter Criteria

  1. In the filter creation window, you’ll see several fields. Focus on the “From” field.
  2. Enter in the “From” field. This ensures that any email from this address will be caught by the filter.

Step 4: Choose Your Filter Actions

  1. Click on the “Create filter” button at the bottom right of the filter creation window.
  2. A new window will appear with various options. To ensure emails from are never sent to spam, check the box next to “Never send it to Spam.”
  3. You can also choose additional actions, such as marking the email as important or applying a label, but for now, we’ll focus on the spam filter.

Step 5: Finalize and Apply the Filter

  1. Once you’ve selected “Never send it to Spam,” click on the “Create filter” button to save your changes.
  2. Your filter is now active, and any future emails from will bypass the spam folder and go directly to your inbox.

Unblocking a sender in Gmail

Occasionally you may need to unblock a sender in Gmail.

33mail emails are sent from a single sender ( so if you accidentally block a sender your 33mail emails may go into spam.

Unblocking is a simple process :

  • Go to your gmail inbox in a web browser
  • Click the gear icon in the top right
  • Click ‘See All Settings’
  • Click the ‘Filters and Blocked Addresses’ Tab
  • Scroll down to ‘The following email addresses are blocked…’
  • Find the address you want to unblock and click ‘Unblock’
  • Click ‘Confirm’ and you are good to go!

Multiple Usernames and Forwarding Addresses

33mail now supports multiple usernames in a single account. You can add additional usernames that forward to your existing account email address or specify a new forwarding address per username. Premium users get 1 additional username included, Pro users get 5, Enterprise users get 25. Your additional usernames will count towards your account alias limits but work the same way as standard usernames otherwise.

You can add additional usernames on the dashboard settings page in the ‘Additional Usernames’ section. Please try out the feature and let us know what you think.

This is why you should be using an email address masking service.

33mail has been operating for nearly 10 years now and a question that I continually get asked is why would someone want to use a service such as 33mail. There are a number of good reasons around control of spam and unwanted email, but right now in a world where every move you make online is tracked, online privacy is becoming one of the primary reasons that people are using 33mail and other similar services.

How you are tracked online?


Most people know that websites can track you via the use of ‘cookies’ which are at their simplest just text that is stored by your browser for a specific website and passed back to that website every time you visit that site.

Cookies are used extensively by marketeers to track what websites you go to and if you purchase goods or services based on certain ad clicks and to actively target you around the web via traditional ad networks. Tracking this way is getting more difficult given the rise of ad blockers and even browsers built to prevent tracking via third party cookies, such as Safari which is working on the ITP standard.

There are 2 types of cookie generally used, first party and third party :

First party cookies are only accessible to the website that they are set on. They are primarily used for tracking login sessions and can also be used by analytics tools such as Google Analytics for session tracking. In a lot of cases first party cookies can add to the user experience within a given website allowing personalized recommendations and analytics for site owners and for the most part they are not an issue as far as privacy is concerned.

Third party cookies are the basis of trackers that follow you around the internet and allow highly targeted advertising. These are what will be heavily restricted by newer privacy focused browsers and their use is generally not a requirement for the web to work effectively so you would be forgiven for assuming that if you use a modern privacy focused browser like safari or firefox you are safe from third party tracking.

The end of the world wide web

The world wide web as it was initially envisioned no longer exists. The web used to be a highly decentralized mix of websites and services which were very loosely coupled, which led to the development of existing cookie based tracking technologies. Current efforts to curtail online tracking only address the internet as it was, not as it is today where the primary interactions that most people have over the internet are are via huge walled gardens such as Facebook, Twitter and Google. These services are based around an identity which is keyed on an email address. This brings us to the problem that email masking can solve.

How are you tracked using your email address

If an advertiser has your email address they can easily use it to target you on any closed network (such as facebook or google) where your email address is the primary form of identity. This means that anywhere that you use your email address, such as signing up for newsletters, online stores or any other online service, can sell your address (or a cryptographic hash of your email address) to marketeers so that they can retarget you in the same way as they would in a traditional cookie based advertising network.

Enter 33mail

This is where 33mail is so useful in protecting your privacy and your online identity from abuse. When you use a new alias for each service that you sign up for there is no way to identify you across these services.

Sign up here and try it out today.

G Suite Catchall Email Address using 33mail

If you manage your domain using G Suite you may be interested to know that you can use it in conjunction with 33mail as a catchall service. This way you get all the benefits of 33mail (easy management of aliases, managed replies, etc) while also routing your primary address through G Suite with all of its features.

Setup is simple but will require a 33mail Premium account (only $12 per year)

NOTE: This feature is only available on paid G-Suite accounts. If you have a ‘Legacy Free’ account It will allow you to set up the route but it will just bounce emails instead of forwarding them.

  • Log into your gsuite admin account and go to Gmail Settings

    • gsuite domain==/AdminHome#AppDetails:service=email


    • From G Suite home :
    • Click the menu at the top left
    • Select Apps -> Gsuite -> Gmail
  • Select Hosts

  • Select Add Route

    • Name : 33mail routing
    • Select Single host
    • Host name:
    • Port: 25
    • Uncheck ‘Perform MX Lookup on host’
    • Uncheck ‘Require secure transport’
  • Click save

  • Select the ‘Default Routing’ Section

  • Click ‘Add Setting’

    • Select ‘All recepients’
    • Select ‘Modify Message’
    • Check ‘Change route’
    • Select 33mail routing
    • In options
    • Select ‘Perform this action only on non recognised addresses’
    • Click save
  • Thats it.

  • Setup your domain in 33mail and G Suite will pass mail for any address not handled by G Suite will be passed to 33mail for processing.

2 Factor Authentication

We have just enabled 2 Factor Authentication for all users. You can access it on the 33mail dashboard settings page.

To activate it on your account you will need a Google Authenticator compatible app such as Authy.

Simply scan the QR code with your app, enter the token and click the ‘Verify & Activate’ button.

If you then log out and log back in again you will be required to input your auth token after your password entry.


A new Email Forwarding Service for your domain by 33mails creator

I have been working for the last few months on a new service to address the need for a simple email forwarding service for your domain which allows users to be onboarded in as simple a way as possible. This stems from a few requests we have had from 33mail users for a similar service.

So picture this :

You are a business owner, Max, who has a number of employees who already have an email account but don’t have an email address at your business domain, say

Joan is one such employee and she already has a personal gmail account but has no idea how to set up a new email account for ‘sending mail as’ in gmail, along with Max not having the time or skillset to set it up for her.


Max sets up his domain on EmailEngine and adds the relevant DNS records, he then just creates a new email address for Joan forwarding to her gmail account and that’s it.

Joan will receive any emails sent to in her Gmail account as they are simply forwarded by EmailEngine, and she can just reply to them as she normally would, but any replies are routed through EmailEngine and the headers modified so that the reply will appear to come from rather than her gmail account.

EmailEngine also supports outgoing smtp if that needs to be set up but at its very simplest it provides a way to let people use business email addresses with zero setup on their side.

I have plans for further enhancements to the service in future but the basic service is now live.

You can check it out here and I would appreciate any feedback.

Pay with your favourite cryptocurrency

We have just enabled payments using cryptocurrencies other than Bitcoin via Just click the button on the invoice page and you will be brought to to complete your premium or pro purchase using cryptocurrencies such as Ether, Dash, Monero and more.

If there is another crypto that you would like to pay with then let us know and we will do our best to enable it.

Check out our updated dashboard

The new site looks very similar to the old one but it has been completely rebuilt from the ground up using the same technology used to build Facebook. The new UI is more functional and much snappier to use. It will also make it much easier for us to add new features in the near future.

Features of note in the current release include :

  • Single page design which makes for a much snappier user experience
  • Full ssl support
  • Updated alias management tool33mail search
  • Simpler Block / Hide buttons33mailblockhide

We would love to hear your feedback on the new site and if you run into any bugs, If you do find a bug please let us know at stating your username along with your os and browser versions.