Whats new in Mailster 3.1?

Today I’m happy to announce the release of Mailster 3.1 – the first big release after our major release in September.

This article gives you a quick overview of the new features. Feel free to comment below if you have any additional questions.

Remove inactive Subscribers automatically

To keep you list clean and healthy it’s a good practice to remove unengaged subscribers from your lists. With Mailster 3.1 you can setup jobs to this for you. This is the first feature request we can marked as completed 🎉.

remove subscriber job
Define jobs with conditions to remove subscribers automatically.

Jobs will run periodically and will mark affected subscribers as deleted. Once a subscriber is marked as deleted you can restore them for 14 days until they get removed from your database.

Learn more on Automation in our docs.

Manage Subscribers got a makeover

Big parts of our manage subscribers section has been rewriting to make im- and exporting easier then ever.

import screen in mailster 3.1
New import screen in Mailster 3.1

Most of our users import their lists from a spreadsheet app like Excel or Numbers so we made sure this works even better as before. You can also import your existing users directly from MailChimp without having to export them first. This makes it super easy to move away from MailChimp and start with Mailster.

We are working on adding more providers in the future so make sure to submit a feature request if you like to see others there as well.

Clean your lists up front with Kickbox (10% Discount)

We’ve partnered with Kickbox which helps you clean you existing lists before you import them into Mailster. Use the coupon code displayed on the import screen to get 10% discount on every purchase.

New relative conditions for date fields

relative conditions

Next to absolute time related conditions – e.g. “is on the” or “is after the” – you can use relative conditions like “younger than” or “older than”.

While this was needed for the automatic list cleanup you can use them now in your regular campaigns and auto responders too.

New subscriber status “deleted”

Whenever you delete a subscriber in Mailster 3.1 it will not get removed instantly but instead marked as deleted. You can then delete them permanently or restore them back. Mailster will automatically delete them 14 days after deletion.

Bonus: Filters in the subscriber overview

You are now able to apply every condition you can use in campaigns or on the manage subscribers page to your subscribers overview.

filter subscriber overview


Mailster 3.1 makes your (email marketing)live easier, your list cleaner and helps you even more to target your audience.

The update is free for all licensee and available via your WordPress Dashboard.

If you don’t own a license yet buy one here.

By Xaver

Founder and creator of Mailster.


Hallelujah! Purging inactives is something I’ve wanted for so long, that I finally wrote custom code to do it.

I will note that I’ve chosen not to delete subscribers, but instead to put them in an “Inactive” list and then unsubscribe them. That way, if someone resubscribes in the future or reaches out and asks me why they stopped getting my emails (it happens, especially since privacy controls are increasingly blocking our ability to see when someone opens an email), then I can see the full history of their subscription.

Also, it’s been critically important to have a winback campaign that runs when someone becomes inactive, and then at the end of that sequence, if they have not taken an action, they get removed.

Hi David!

I like the idea of your “winback campaign” but this can work already if you send to who received but didn’t opened (or better didn’t clicked since iOS 15).

Maybe ask if they still like to receive your updates and move them to a list or tag.

Hi, I have a question about the segmentation feature. I have recently sent out an email regarding Covid-19 restrictions. There are around 60% of the receivers who has opened the mail. I would like to send an other mail to whose that don’t has opened the mail. I choose in the conditions area in the editor to send the mail to “has received but not opened” the first campaign. According to the result : 0 receivers. How can that happen, it should be 40% of the original amount of the receivers. Is it a bug?

Hi Henrik!

Sounds like a bug to me. Please open a ticket and we’re happy to investigate. We’ve already tracked down one which should be fixed in 3.1.1 next week.


Mailster just keeps getting better with intriguing additions such as: added: filter mailster_campaign_meta_defaults

Can you please point me to where this is documented — hopefully with an example ?


Hi there, I wonder if the subscriber gets a notification when restored? “Once a subscriber is marked as deleted you can restore them for 14 days ” I deleted someone in a disagreement and wouldn’t want them to know …

The subscriber doesn’t get notified about this but of course can re signup to your list. You can block an individual email addresses on the security settings page.

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