Email Scrubbing: The Ultimate Guide

Aug 26, 2020

In the world of email marketing, you can think of addresses like milk in a convenience store. It’s only good for a certain period of time and once it’s past its due date, you really do not want to drink it.

To get the most out of your email marketing efforts, you want your lists to stay up to date. As a result, you’ll get fewer spam complaints, lower bounce rates, better email deliverability, higher conversions… And more.

To get there, you need to do some email scrubbing. And today, we’re going to show you what it is and how to do it.

What is email scrubbing?

Scrubbing is an industry term for email list cleaning services and removing email addresses that are of no use to you. Scrubbing helps you attain your best possible sender reputation and improve your deliverability.

There are a few reasons to do email scrubbing.

  • Emails decay. After a few months, many email addresses are not being used anymore
  • There could be typos and errors in the emails that people submit
  • Website visitors could submit fake emails to your opt-in forms, resulting in fake email subscribers on your list
  • There could be duplicate email addresses in your email marketing software
  • There could be disposable email addresses that people use just to sign up for your product and never use again

All of these mean that you could be sending emails to outdated or non-existent addresses, which has a deep impact on your email marketing metrics such as your email bounce rates, open rates, click-through rates, and more.

reasons for cleaning an email list


Benefits of email scrubbing

It’s all about metrics, and how they affect your results.
The ISPs keep a close eye on how your email marketing campaigns are received on different email servers. They use that data to determine whether you’re a great/good/unwanted source of information for their users and whether you have engaged or unengaged subscribers.

If you send out an email and it gets deleted without being read or sent straight into the spam folder, your ISP knows. If too many of your recipients do the same, then the ISP decides you’re not a valuable source of information and sends you to the spam folder itself—or worse still, blocks your domain.

Scrubbing your email list will result in:

  • Fewer spam complaints
  • Better open rates, click rates, sender reputation and inbox placement
  • More efficient allocation of budget
  • Improved performance, metrics and ROI – all with a clean email list

Things to take care of before a good scrubbing

There are a handful of things every good marketer needs to know before making hasty decisions with email list scrubbing. Accurate data is everything. It removes the guesswork from our decisions.

Checking a few simple areas could hold the answers to why your emails aren’t getting opened; saving you from deleting what could be active and worthy email addresses.

  • Can you work out why emails are bouncing?
  • Are you collecting email addresses using opt-in methods or an alternative two-factor authentication?
  • Do you communicate with your active subscribers to find out why they might have lost interest?

How to scrub your email lists?

The most effective way is to use email list cleaning services. Here are the basic steps of a proper email list hygiene:

  1. Segment your email addresses list
  2. Clean the segment
  3. Attempt to re-engage your freshly cleaned segment
  4. Delete the bad email addresses from your list
  5. Check the automated responses to your email marketing campaign

Each email delivery app has its own ways of organizing itself, and what it calls its elements—but ultimately they’re all there to do the same job, and they work in very similar ways.

If you can’t locate the areas we talk about, search through your email service providers’ help files, and they’ll turn up—only with a different name or slightly different action.

Step 1 – Segment your list

The first thing to do before scrubbing a contact list is to take all of the suspect email addresses to one side to determine if they’re worth keeping or not.
You do this by moving unengaged subscribers who don’t interact with your emails anymore into a list of their own. You do this using ‘segments’.

Find the ‘create a segment’ option in your list management, and there will be an option for inactive or cold subscribers. They both mean the same thing. In fact, your email marketing tool might call it something different again (but it’s unlikely). Inactive (or cold) subscribers are the subscribers on your list who haven’t opened any of your emails for 90 days.

If a subscriber hasn’t opened any of your emails for 90 days, it’s unlikely they’re going to during the next 90. 

It’s assumed most businesses send at least one email each week; that’s about a dozen emails over 3 months. It outlines a habit that’s more than likely already stuck. Why would they do that? Well, it’s easier than unsubscribing. You could leave them as they are but that’s actually harming your email marketing strategy.

If your software doesn’t include a cold/inactive option, then choose your own parameters.
Your segment could include all email addresses that didn’t open any of your previous 5 or 10 email campaigns. It’s the same type of segment, only a different set of search criteria.

Perform the search for all of your inactive or cold subscribers and segment them.
Download them into a new spreadsheet containing the addresses, and move on to Step 2.

Step 2 – Clean your inactive addresses segment

If you’re an eagle-eyed superhuman with all the time in the world—or you have a really small list—then you could do this manually and keep your email hygiene spotless.

What you’re looking for is misspelled and fake email addresses, yet that’s only half the battle.
This is where you can’t beat using email scrubbing software to do the hard work for you.

Bouncer is ready to help

Not only does our email scrubbing service track down misspelled, and fake addresses and remove inactive subscribers, but they also check for all kinds of bounces (hard and soft bounces), duplicates, expired and invalid email addresses, non-existent domains, and more. It’s far more thorough than you could ever be, and a hundred times faster.

Scrub an email list for free

That’s right. Bouncer gives you 100 credits absolutely free to get you up and running with email list cleaning services. It’s also a great opportunity for us to show you how beneficial our email verification tool is, and how much it will add to your ROI and streamline your budget.

Running your subscriber list through our email list cleaning services will leave you with a new list of email addresses that are getting delivered, yet sadly, ignored. So, what do you do with them?

You could unsubscribe the lot and have done with every single email. Or, you could give them one last chance to do something with re-engagement campaigns. On we go to Step 3.

Step 3 – Can you re-engage your inactive subscribers?

Consider why your subscribers aren’t reading your emails.

  • Did they lose interest?
  • Did they someone cheaper?
  • Did the email quality drop off?
  • Did they change their email preferences?
  • Do they no longer need what you have to offer?

Whichever reason (apart from the last one, of course…), there’s a possibility that with the right information or offer, you could win them back with a proper email program.
So, ask them what they want.

If they don’t reply, then that’s it. The love affair is over, they’re inactive users and it’s time to unsubscribe them for good.

If they do reply, can you use that information to get them back on the hook? Perhaps, squeeze in a few more sales from them? Or at the very least, garner a few more clicks to bump up your metrics?

Here’s what your re-engagement email could offer:

  • A discount on their next purchase
  • A free gift with their next order
  • Access to premium services in your re-engagement emails

Alternatively—why not just ask them if they want out? If they’re just not interested anymore, then they’re no good to you. They’ll never be a good customer, at least, not any time in the near future. So, lead your emails with the following messages (or similar) and ask if they’d like to unsubscribe.

  • We miss you!
  • Where have you gone?
  • Was it something we said?



Okay, you lose a few numbers from your list, but your metrics jump up, as does your list quality. You may have a smaller list, but it’s a clean list you can send marketing emails to. It’s a clear win.

Step 4 – It’s time to say goodbye for good

Well, maybe not for good. Yes, they need to go from your list—they’re doing nothing but harm on there—but save those email addresses in another spreadsheet in case you can use them somewhere else in your future email marketing efforts.

If you need to target ads on other platforms, for example, Facebook or Google Ads, this list gives you a clear headstart when you’re launching a new product or service, or breaking into a new market.

Otherwise, head back to your inactive subscribers’ segment, delete all of the users it holds, and then upload the salvaged emails back into your list.
Job done. Treat yourself to a coffee for a good start of your successful email list cleanup.

Step 5 – Check for automatic response emails

This is the final part of your scrub.

Depending on how large your list is, it could take quite some time, but any addresses that you find and remedy, are all small steps for the greater good. Only you can judge the value of a truly scrubbed list against your time.

For many, this might not be worth the effort, but taking a few minutes here and there could add an extra level of sheen to your all-new shiny metrics.

If a reply to your campaign looks like a robot sent it, and not a human, you should use that information as part of the process.

Automated emails uncover a host of truths.

  • The address is no longer valid
  • The employee no longer works here
  • The recipient has changed departments
  • They’re out of the office

Whatever they say, you’ll be able to determine if the address is valid for your needs. If they’re out of the office, have they really been absent for 90 days? And if so, are they worth keeping? If they’ve moved, changed jobs, been fired, or disappeared into thin air—it’s time for them to go.

That’s it! You’re all scrubbed up and ready for your new streamlined results

With a streamlined email addresses list, your rates of engagement will improve significantly—just as you need them to. Not necessarily because you have more opens and clicks, but because you have far fewer poor and inactive subscribers dragging your quality metrics down.

The ISPs work on percentages, remember, not just the number of clicks. If you’re sending out a thousand emails and fifty people open them, your sender score will be much higher than if fifty people opened the same message, but without sending it to the two or three hundred addresses that were never going to open it in the first place.

Better for your metrics, and better for your budget. It’s a win-win, and all it takes is good email scrubbing.

Wrapping up

Email scrubbing may seem like a chore, but a proper email cleaning service can help you get it done in no time. You’re looking at better email metrics, higher engagement and more conversions from your existing lists – what’s not to like?

If this sounds like a plan, try our email verification service today, completely free. With Bouncer on your side, your lists will be cleaner and your email marketing ROI will be through the roof.

Grab your free trial now!

Frequently asked questions

How often should I scrub my email lists?

It depends on how many emails you have and how quickly your list is growing. However, once every six months is a pretty good practice that email marketers should follow.

What is the fastest way to scrub a large email list?

By using email verification services such as Bouncer. Removing inactive email addresses and duplicate emails manually is very time-consuming and would take weeks for larger email lists.

Is there a downside to email scrubbing?

There are no downsides, except maybe seeing a smaller number of subscribers on your email list. However, you will end up with a healthy list, a higher deliverability rate and overall better email marketing ROI.


Scrub your email list with Bouncer

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