5 Simple Steps to Avoid the Spam Filter


Keeping Your Email Marketing From Getting Caught in a Spam Filter Isn’t as Hard as You Think

Note: First posted in Sep 2016, this blog was completely rewritten on 21 Sep 2018 to accommodate the changing landscape of spam filters.

Let’s face it, as individuals, we all benefit from spam folders. If we didn’t have them, email would fail as a viable channel for communication. The flood of scammy offers for suspicious pharmaceuticals and foreign bank transfers would drown out any meaningful communication.

But sometimes spam filters cause problems for legitimate email marketers practicing permission marketing. This happens when a spam filter identifies a “false positive” – when it marks an email as spam that isn’t spam. If this happens repeatedly, senders can even end up on a blacklist. This means their emails won’t even make it to the server where the recipient’s inbox lives.

We recently posted an extensive blog post that answers all your questions about spam and email deliverability.

We go into detail about how spam filters work, what blacklists are, what the finer points of email deliverability are, how the term spam evolved and what aspects of email deliverability an email service provider (ESP) should provide. We’ve got an email delivery glossary and actionable content upgrades for you. But ….

There was one topic, though, that was so important we decided to spin it off into a blog post of its own. People ask us over and over again: “How do I keep my email out of the spam folder?”

If you’re worried about this happening, keep reading. We’re here to tell you the five steps to preventing your legitimate email marketing from landing in the spam folder.

Step 1️⃣: Use an Email Marketing Tool for Mass Mailings

To many, this may seem like a no-brainer.

But it’s important to remember the ultimate first step to avoiding the spam filter. For lots of technical reasons, if you try to send email to lots of people through your regular inbox tool, it won’t work.

Using Gmail or Outlook, or even an outdated CRM too, to send out mass mailings will just get you blacklisted. Inbox providers, (also known as internet service providers, [ISPs]) will detect that you are sending mass mailings, and they will dump them right in the spam folder. Or blacklist you outright.

This is why ESPs, such as Newsletter2Go, which offer email marketing software, exist. So you can send out emails that actually arrive in people’s inboxes. So you don’t have to worry about the highly technical aspects of avoiding spam filters.

Don’t have an email marketing tool yet? Check out our (only slightly biased!) list for what to look for in your software.

You already have an email marketing software? Great! You’ve already taken the first step towards avoiding spam filters.

Step 2️⃣: Set Up Authentication Methods

There are several verification methods that you can set up to boost your deliverability.

These are technical processes that prove to the inbox provider that you are legitimately who you say you are. These prevent things like address spoofing.

The two most common ones you should make sure you have are DKIM and SPF. We also offer Sender ID, which is based on SPF. Set these up in your backend and you’ll be in really good shape.

Also, if you end up needing dedicated IP addresses, make sure you have DMARC.

Step 3️⃣: Learn What Spam Is & Don’t Send Spam

Spam is unsolicited commercial email. That means if you’re sending email marketing that someone hasn’t agreed to receive, you are spamming.

Spamming is also known as “mass cold emailing.”

In many corners of the world, spamming is illegal, and companies that cold-email put themselves at risk of massive fines. Throughout the EU and also in Australia and Canada, promotional emails to contacts without their consent is illegal.

Spamming is also known as “mass cold emailing.” #DontBeASpammer Click To Tweet

What’s more, thanks to the GDPR, it is now not only illegal to cold-email from the EU, it’s also illegal to cold-email to the EU. If any of the recipients on your contact list live in the EU, the best legal practice is to comply with GDPR and not cold-email them.

The U.S. forms an exception to this pattern. Sending email marketing without prior consent is permissible under the U.S. CAN-SPAM Act. If none of your contacts are in the EU, that is!

Now you know what spam is.

So you can take the second step to keep your email marketing from landing in the spam folder:

Don’t spam.

Only send to people who have agreed to get your marketing. But how do you find those people and go about doing this?

➡ Use Double Opt-ins (DOI) Forms to Grow Your Email List

The best way to make sure your email marketing only reaches people who gave explicit consent to receive your emails is to set up a double opt-in sign-up form.

Promote this form everywhere – as a signature link in your work emails, on social media and as a pop-up or overlay on your website. You can also consider incentivizing subscriptions by offering something in return for signing up for your email list.

Opt-in means that people are choosing to receive your communications. They do this by entering their information on your form.

A double opt-in means that you send them an email after they input their email address. In this email you ask them to confirm their registration with you. This is also called a confirmed opt-in.

Why is this important?

If you use a double opt-in process, then you are confirming that the person behind every email address who signs up for your newsletter actually has access to the inbox they say they do.
If you use a double opt-in process, then you are confirming that the person behind every email address who signs up for your newsletter actually has access to the inbox they say they do. #DOI #EmailMarketing Click To Tweet

If you skip it, you might end up sending emails to people who never signed up for your email. Which means you’re sending … spam.

Any good email marketing software provides you with the mechanism for setting up a double opt-in form.

We cannot stress enough how important this is. If you skip this step, you’ll eventually send email to someone who did not sign up for it. This person will not hesitate to report your email as spam. You also might end up with spam traps on your list.

Pro Tip: Start growing your email list as soon as possible. Before you’ve even launched your newsletter or your full website!

➡ Insert Unsubscribe Links to Your Mailings so You’re Not Holding People Hostage to Your Marketing

While it might sound counterintuitive for some, a visible unsubscribe link or button in every email is a must. Most email marketing software offers this as a standard component of all templates.

Remember that spam means unwanted commercial email. It also happens that people change their minds and decide they don’t want your email marketing anymore. If they do, you want to make it as easy as possible for them to remove themselves from your list.

It’s much worse for your sender reputation if a recipient marks your email as spam than if they unsubscribe from your email list.

Most consumers receive hundreds of emails a day. They will not hesitate to hit that Report Spam button in their email client if they don’t see an easier way to stop your emails.

Most countries, including the U.S., require you to have an unsubscribe link in every email marketing communication you send.

And, depending on the country, you have a short time frame to respond to unsubscribe requests. In the U.S., you have 10 days to remove someone from your mailing list after they have unsubscribed.

Unsubscribe links and DOIs are the cornerstones of permission email marketing.

Have you already done these two things?

Congratulations, you’re not a spammer! You’ve already completed the first two steps of avoiding the spam filter.

Pro Tip: Point out the unsubscribe button to your recipients in a p.s., and you’ll gain their goodwill. You’ll also boost the chances that they hit unsubscribe instead of reporting you as spam.

Some phrasing for doing that, ranging from formal to informal:

  • If you no longer want to receive promotional communications from us, please follow the unsubscribe link below.
  • Not interested in hearing from us anymore? No worries at all! But please hit the unsubscribe button in the footer instead of marking this email as spam.
  • We’d be bummed if you no longer wanted to get email from us. 😢 But we get it. Life is short. That’s why there’s an unsubscribe link below.

➡ Do NOT Buy Email Lists

This point should be obvious to you, but it’s worth mentioning. Buying email lists will land you right in the spam folder. Recipients on the list never agreed to receive communications from you. There’s a high chance that such lists are sold without the consent of the subscribers and are illegal.

Also there will definitely be spam traps on that list. What are spam traps? More on that in our deliverability post! Just know that your sender reputation will suffer and an increasing number of your emails will land in spam folders if you are emailing spam traps.

If you feel the urge to buy an email list, just say no. Think about how you can incentivize your email list subscription instead.

Step 4️⃣: Send Content Relevant to Your Audience’s Interests

It sounds so simple, right? But actually, it’s really difficult. And we understand that, we really do. But, listen up: Providing relevant content is the biggest single thing you can do to avoid falling prey to the spam filter.

All the articles on the internet telling you to run your email through a list of known spam-trigger words? Focusing on that is a waste of time.

Inbox providers (also known as ISPs, internet service providers) measure recipient interaction with your marketing emails. Of course, they also make decisions based on this.
Providing relevant content is the biggest single thing you can do to avoid falling prey to the spam filter. #EmailMarketing Click To Tweet

You’re looking at your contact list’s opens and click-through rates, while Gmail and Outlook and Yahoo are looking at even more granular behavior.

They are measuring number of times forwarded, emails deleted without being read, emails marked as read, how long you spend reading an email, emails rescued from the spam folder and emails sent to the spam folder. These key performance indicators are known as engagement metrics.

Some inbox providers make them available through feedback loops. Most, however, keep these metrics secret.

But don’t stress too much about these hidden metrics that influence your sender reputation. Because, truly, what are they but a sign of relevant content?

Your mission, then, becomes to write emails and subject lines that are so compelling that no one will want to delete your email without reading.

How do you create relevant content?

➡ Know Your Audience

It’s a truism because it’s true. Successful email marketing is just like any other marketing.

You have to understand your email subscribers. Why did they subscribe? What knowledge would help them be more successful? What do they care about? What issues are they facing?

Ultimately, like in all content marketing, your job when writing emails is to share your expertise in a way that informs your clients. Teach them how to succeed. And make it seem that much easier to succeed with you.

If you don’t know your subscribers well, reach out. Here are some ways to do that:

  • Send surveys and create customer personas based on these.
  • Call up a few customers and talk to them about their pain points and benefits. Ask them what they struggle with the most and how your expertise can help.
  • Or, in a pinch, go and talk to your sales team.

You can’t send relevant information to your customers until you understand what relevant means to them.

And if you’re wondering what questions to ask in your survey or calls, here are five ideas to get you started.

    1. What would help you use [our products/service] better?
    2. What knowledge do you feel you’re lacking in the area of [your industry]?
    3. What do you wish you knew more about when using [our products/services]?
    4. How frequently do you use [our products/services]?
    5. What are the top three biggest challenges for you at work or in your daily life that [our products/services] could improve?
1. What would help you use [our products/service] better? 2. What knowledge do you feel you're lacking in the area of [your industry]? 3. What do you wish you knew more about when using [our products/services]? 4. How frequently do you use [our products/services]? 5. What are the top three biggest challenges for you at work or in your daily life that [our products/services] could improve?

➡ Knock the Ball out of the Park on Every Single Subject Line

The subject line represents the most important text you will write for each campaign.

It needs to deliver emotion, such as urgency, curiosity or excitement.

It should also be short. The shorter the subject line, the higher the open rates. Check out our guide to writing the best email subject lines.

The shorter the subject line, the higher the open rates. #EmailMarketing #TrueFacts Click To Tweet

Also, once your audience is over 500, it’s time to start A/B testing your subject lines. Test everything from what kind of capitalization works better on your target group to which type of emotional writing they respond to.

➡ Insert More Content Than Images

No matter how beautiful your email template and images might be, your mailings still need to include text. Most inbox providers treat content-free emails as spam. So make sure you have more text than images!

However, that doesn’t mean you need to spend hours on content creation. Newsletter2Go’s 1-click content transfer works wonders. With it, you can directly import your content from a CMS, such as WordPress, into your newsletter

➡ Link Only to Reliable Sources & Avoid URL Shorteners

Spam filters inspect the email content, particularly the links you send. Link shorteners hurt email deliverability, as do links to unreliable websites.

Link shorteners are often abused for phishing email as they can hide the sender’s true domain.

What’s more, if you and a known spammer use the same link shortener in emails, then one or even more inbox providers will start blocking emails with the link-shortening domain. While the inbox providers aim to block the spammers, there’s a high chance that your emails will find their way to the spam folder, too.

And what counts as a reliable website? Anything created by an obviously legitimate organization. Check their About Us if you’re not sure how legit a website is. And if in doubt, don’t link. Government (.gov) and academic (.edu) domains hold the most weight.

The Online Erotic Shop: A Mini Case Study in Relevance Trumping Spam-Trigger Words

Here’s a story that illustrates what we mean when we say that sharing content relevant to your customers’ interests is more important than picking so-called spam-trigger words out of your content.

As spam filters have become more advanced in the past ten years, they’ve come less to rely on “spammy words.” It’s particularly engagement-based metrics that have changed this.

If you google how to avoid landing in the spam folder, you’ll encounter ultra-long lists of spam-trigger words. There are hundreds of lists out there. They range from pharmaceutical terms; to urgent CTAs, such as “buy now,” “today only,” “free”; to sexual vocabulary. You might take one look at those lists of words to avoid and want to run for the hills. Because everything is on those lists – including sales and marketing terminology. Even phrases like “email marketing,” “Dear” and “#1” pop up a lot.

Don’t sweat it. Actually, ignore those lists completely. They are not what matter. What matters is relevance. If your subscribers read your emails, then that will be enough for the spam filter.

One of our most-successful customers of all time was a well-known erotic shop.

Given the nature of what they sold, their emails were jammed full of sexual vocabulary – words which any spam-trigger list will identify as absolute no-gos. I’ll leave the content of their emails to your imagination, but I’m sure you get the picture.

They consistently had open rates of 60–70%, some of the highest we’ve ever seen a client maintain over time.

Why? Because they were brilliant at email marketing.

They offered email courses about topics that people cared about. They delivered solid information, e.g., how to build your self-confidence and how to communicate openly about difficult sexual topics. They provided content that was relevant to their clients. Within that content they subtly interwove CTAs about their products. That means those emails converted like crazy.

Because their subscribers valued the emails they received from this erotic shop, they never had a single problem with the spam folder.

Maybe you’re thinking, “But my product is literally not as sexy as that.”

But you don’t have to be an erotic shop to draw people’s interest. Whatever products or services you sell, you are an expert in its use. And your subscribers signed up for your list because they want to learn from you.

You know how to use your product or service, and your clients will benefit from this expertise.

So share your expertise, provide them with information, and you’ll never end up trapped in your contacts’ spam folders.

Step 5️⃣: Maintain Good List Hygiene

You’re nearly there. You’ve signed up for an email service provider. You’ve learned about spam and made sure you’re not spamming. You’ve grown a loyal email base and people are reading your emails because you’re delivering relevant content, not just blasting out promotions. Now it’s time to talk about list hygiene.

The verb people often use when talking about emai lists is “growing.” And that’s exactly what you are doing by collecting new subscribers, you are “growing” your email list.

Now, any good gardener knows that you can’t just plant some seeds in your garden, water them a lot and hope to get a beautiful crop. You also have to weed your garden.

Email list hygiene is as necessary to email marketing as weeding is to gardening.

You want to make sure you are only sending to engaged, active email contacts.

Email list hygiene is as necessary to email marketing as weeding is to gardening. Click To Tweet


For two reasons.

  1. It will boost your engagement-based metrics and up your sender reputation.
  2. It will eliminate spam traps from your list. There are a lot of old email addresses out there that blacklist providers (and some ISPs) have converted into what’s known as spam traps. The sole purpose of spam traps is to catch spammers.

If you send to a spam trap, it will hurt your sender reputation. It sends a signal to ISPs that you are not taking care of your list.

➡ Remove Inactive Accounts

A bounce address is an email address that is no longer receiving email.

A hard bounce means that the address has been deactivated, and a soft bounce means that it is temporarily not receiving email, perhaps because the inbox is full.

You should send your email campaigns only to actual email addresses. This means you need to be managing bounces.

Most email marketing software has automated bounce management, which deals with hard and soft bounces.

For example, we automatically unsubscribe all hard bounces. And our software considers three bounces to be equivalent to a hard bounce. If your email marketing software doesn’t have automated bounce management, make sure you are monitoring these addresses yourself. Remove all hard bounces from your active contacts, and keep on an eye on how often an address soft bounces.

➡ Consider Removing Contacts who Don’t Engage

If you send emails out twice a month, and someone hasn’t so much as opened an email from you, do you think they still want to receive your emails?

How to handle unengaged subscribers is a topic of much debate in the email marketing community.

But, the fact of the matter is that you want to be sending to people who want to read your email. If they aren’t opening it, then they’re just dragging down your open rate and missing out on your content and deals.

Now, this doesn’t mean you have to start deleting contacts willy-nilly.

Give them a chance first to let you know if they still want to hear from you. This is called running a re-engagement campaign for inactive subscribers. If you are in e-commerce, you can also set up a reactivation campaign for those who haven’t purchased in a long time.

We recommend running a re-engagement campaign regularly. If you send monthly or more frequently, then you’ll want to run a re-engagement campaign about once a year.

You can set this up as an automated campaign that runs every time someone goes a year without opening an email from you. Or you can choose a particular time of year to do this manually.

If you only send quarterly newsletters, then run your re-engagement campaign less often, e.g., every two years.

➡ Set Up Contact Profiles for Managing Subscription Preferences

Market research shows that the more control you give recipients over the emails they receive, the more likely they are to stay subscribed to your email newsletter.

Consider setting up a subscription profile for each recipient.

Market research shows that the more control you give recipients over the emails they receive, the more likely they are to stay subscribed to your email newsletter. Click To Tweet

Most subscription profiles just provide a space to change your name and email address. But you can ask more. Provide fields for them to select how often they receive emails from you, what topics interest them and which language they’d prefer to receive your emails in, for example.

Attach the fields to specific auto-update segments or contact lists and automate and personalize accordingly.

Pro Tip: Set up at least two auto-update segments for sending frequency. Let subscribers choose between daily, weekly and monthly emails from you. (Or whatever frequency fits your capacities.) Alert your subscribers to these options in the text of your welcome email.

Hey, Big Senders!
Bonus Step 6️⃣ for Those Who Send A LOT: Control Your IP Reputation

If you’re sending a lot of emails every month, then we have a few extra tips for you to avoid the spam folder.

What do we mean by a lot? If you send 100,000 emails a month or more, then we are talking to you.

You need more control over your IP reputation. This is how you get it.

Does your company send an email volume of at least 100,000 emails a month or more? You should definitely be looking into dedicated IP addresses. #EmailMarketing Click To Tweet

➡ Send Mailings From Dedicated IP Addresses

We recommend that big senders choose an email service provider that offers dedicated IP addresses.

A dedicated IP address means that you are the only company sending from this IP address. Other clients share a pool of IP addresses.

This gives you a chance to develop your own IP reputation, which is the most important technical factor in passing the spam filter.

Most email service providers offer this service. They should also give you the advice and guidance you need when you purchase this service.

But in case they don’t, here are some tactics you should discuss with them when setting up dedicated IP addresses.

Pro Tip: Keep your email terminology straight!

Transactional content is a mailing about account information, invoices or delivery information.
Promotional content is an email selling something.
Informational content is a how-to email or another email sharing expertise for the recipient’s own benefit.

We recommend mixing promotional and informational content in one mailing. But always send transactional mailings separately and from their own IP addresses.

➡ Send Transactional Emails and Marketing Emails From Separate IP Addresses

You want a 100% open rate on transactional emails. Which your marketing emails just aren’t going to get. You essentially need to establish two IP reputations – one for transactional emails and one for marketing emails.

Otherwise, the lower open rate on your marketing emails could harm the deliverability of your transactional emails.

You can also separate out the domains you are sending from, but sending from too many related domains can look spammy.

Diversify your IP addresses, but don’t diversify your sending domain too much.

➡ Send Regularly

If your business model drastically changes and you are sending fewer emails, then you’ll want to quickly revert back to pooled IP addresses.

Not sending regularly will harm your IP reputation. Only buy dedicated IP addresses if you plan to keep sending lots of email.

➡ Warm Up or Prime Your IP Addresses

You can’t just start sending mass email from a “cold” IP address, that is, one that has not yet been used to send email. That IP address has no IP reputation. And having no IP reputation is actually much worse than having a poor one. Emails sent from a cold IP address will get marked as spam or rejected outright.

Chances are your email service provider will handle this for you. Inquire if the dedicated IP addresses you’re getting are already “warm.”

If they’re not, you’ll have to warm them up yourself. This is also called priming your IP address.

Having no IP reputation is actually much worse than having a poor one. #EmailDeliverability Click To Tweet

Here’s a brief description of how to prime your IP addresses.

You have to start sending emails in a trickle, preferably to recipients you know will read them. Do this to establish a good reputation with the inbox providers, and then gradually increase how much you send over time.

In Sum …

Do these five things to keep your emails out of the spam filter:

  1. Use an email marketing tool for mass mailing
  2. Set up authentication (DKIM & SPF) for your mailings
  3. Send campaigns only to recipients who have agreed to receive it
  4. Provide your contacts with content relevant to their interests
  5. Practice regular list hygiene

Bonus step for big senders: Control your IP reputation

Did you know that Newsletter2Go rewards good marketing? We’re on a mission – to improve the quality of email marketing globally. For starters, we’ve got a free resource center to educate you on how to grow your business with email marketing. Not only that – we put our money where our mouth is. When you use our email marketing software, you get money back for emails that perform well!

Learn how to earn money back for good email marketing.

About the Author

Mara Taylor
Online Marketing Manager at Newsletter2Go

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