Stay Out Of The Spam Folder With These 12 Tips And Tricks


The world of email deliverability can be a frustrating place.

Similar to how Google keeps adjusting its search algorithm to provide the best results, companies must also regularly adjust their tactics to ensure that their emails reach the inbox. 

Internet Service Providers (ISPs) are waging an endless war against spammers. Mashable reported that over 70% of emails are considered junk, bulk, or spam mail. It’s been estimated that 100 billion spam emails are sent daily.

This war has heavy casualties in the form of “false positives”. Every sender, no matter how conforming, will experience inboxing and spam issues at some point.

As rule-abiding as you are, your legitimate commercial email campaign can be mistakenly routed by spam filters to bulk folders.

If you want to be one of the good guys, aim to always be:

  • Sending the right message,
  • To the right person,
  • At the right time,
  • With the right frequency

In this post, we’ll offer you some of our best advice to ensure that your emails avoid spam filters and get delivered to your recipient’s inbox.

1. Build your own email list

Organically building your email list is not the easiest nor the fastest way.

But it’s the most effective in the long run.

If buying lists ever crossed your mind, remember that sending emails to those who have not agreed to receive them sinks your sender reputation faster than any other email offense.

Sender reputation and email delivery are the sender’s responsibility, your responsibility. Not an Internet Service Provider’s (ISP) or Email Service Provider ‘s(ESP) responsibility.

What you say in your emails is indeed incredibly important. But your content doesn’t mean anything if you’re saying it to the wrong or to an unengaged audience.

Take your time when collecting email addresses to cultivate a healthy list of recipients who have agreed and look forward to receiving your email.

Always avoid:

  • Renting or purchasing an email from a third party;
  • Sharing or using a shared list with a partner;
  • Email harvesting (using a robot to collect emails).

Purchased lists are ticking time bombs, full of dead emails and spam traps. They quickly inform mailbox providers that you break the rules by sending unsolicited emails. Just like that your sender reputation goes down the drain.

At best, your messages may end up in junk folders.

Worst case scenario, you may be branded as a spammer.

2. Provide a double opt-in

Setting up a clear opt-in process establishes expectations and defines the relationship with your recipient right from the start. Not to mention is also avoids spam traps.

Which in turn will keep your engagement and deliverability rates high.

 A double-opt-in method provides a subscriber with a welcome email that they must confirm before they officially end up on your email list. This form of opt-in is very similar to a confirmed opt-in.

This is the best method for collecting email addresses. It’s how the sender demonstrates he wishes to ensure the recipient absolutely wants their content.

Using double opt-in forms results in more qualified email lists and engaged subscribers.

You may also want to consider including a reCAPTCHA feature to your email sign up forms. A reCAPTCHA verifies that the soon-to-be recipient is a human, not a spambot signing up for your email.

3. Authenticate your email with SPF, DKIM, and DMARC

Email authentication can be tricky, but it lends a greater degree of trust to your mail streams. This is important to set up, because validated email senders are more likely to stay out of the spam box. 

Authenticating your email verifies that you are who you say you are. Inbox providers, such as Google and Yahoo, trust authenticated email more and are more likely to deliver mail from such an email address.

So, you will want to make sure your email server supports the protocols descibed below (DKIM, SPF, DMARC) and that they are properly implemented.

The following methods authenticate your email and prove to the ISPs that your email is worthy of the inbox:

Sender Policy Framework (SPF)

SPF is an email authentication standard that compares the email sender’s IP address to a list of IP addresses authorized to send email from that domain. The IP list is published in the domain’s DNS record.

Domain Keys Identified Mail (DKIM)

DKIM ensures that an email has not been tampered with during transmission. You can think of it as a wax seal on a letter. If the letter’s seal remains sealed upon delivery, it was securely transported.

Domain-Based Message Authentication Reporting and Conformance (DMARC)

DMARC is a more sophisticated authentication method that leverages both SPF and DKIM to prevent email spoofing (forging a sender address).

Each layer of authentication brings you a step closer to a very low spam score. It drastically reduces your risk of missing the inbox and landing in spam.

4. Regularly clean your email list

A smaller, more engaged email list is better than a massive, but unengaged list.

The quality of your list is much more valuable to your business than the list quantity. Properly maintained email lists will also help you avoid spam traps.

Ideally, you should clean your email list using an email list cleaning service, like Verifigator, which can validate email addresses without sending email.

It can clean any existing mailing list from invalid and suspect email addresses and it can be used in real-time to prevent invalid email addresses ever being added. Also, Verifigator detects special email inboxes, such as spam traps, fake email addresses, one-time use and disposable emails and role accounts.

Your audience will receive what they want to hear, you will improve your deliverability rate and your conversion rate.

Email provider’s spam filters penalize your domain or IP with a higher spam score if they see that you are sending emails to bad email accounts. A bad email account is an address that doesn’t exist, has been disabled, has a full inbox or the recipient is simply ignoring your email.

Keep in mind that many who no longer want to receive your email will simply ignore your emails instead of unsubscribing.

This is actually harmful because the lower your email engagement rate, the less favorably you will be viewed by the ISPs. Monitor email engagement across your list(s) to ensure your email campaigns are sent to the most engaged users. 

In order to combat low engagement, regularly remove inactive recipients, bounced emails, and role email addresses. By being proactive you’ll experience improved email deliverability rates.

5. Get on the White Lists

This one still remains one of the best ways to stay out of the spam folder.

Your Email Marketing Service (EMS) asks mailbox providers, such as Gmail and Yahoo Mail, to whitelist your domain or Internet Protocol (IP) address. That’s why it’s important to send marketing emails through a reputable EMS, rather then sending emails from your own email server or email account.

This will ensure that your subscribers are receiving the emails they signed up for. However, if you send a particularly spammy email you can be removed from the list. The process can be quite frustrating and take some time, but it’s well worth it.

Most spam filters allow you to whitelist certain senders. So, when new people subscribe, tell them how to add your email address to their whitelist or safe sender list. You can show the whitelisting instructions directly on the “Thank You” page and then repeat them in your first newsletter. 

Also, having more people whitelist your emails will help to increase your sender reputation. Plus, your inbox delivery rates will be higher overall.

6. Know your audience

The more information you can collect about your audience, the better.

I’m not suggesting you to be a stalker, but the basics of knowing the first and last name of each person who subscribes to your email list will be a huge help.

Not only does knowing who you’re sending to create a better overall experience, it also verifies to spam filters that you have a connection with the recipient when you’re using their name in the TO: field.

Additionally, people are hesitant to open emails from unfamiliar senders, which is why you should either use your brand name or real name as the sender. Personalizing your emails will also increase engagement and open rates.

7. Provide a clear unsub link

Nobody likes it when somebody unsubscribes from their email list. 

But no matter how valuable you think your email campaigns are, you still need to give your subscribers a potential out. It’s actually illegal to not offer an option for people to unsubscribe.

The number one reason for ending up in the junk box is the number of spam complaints that you receive. Avoid them at all costs.

Providing a clear way to unsubscribe and then honoring that unsub quickly means that users are less likely to get annoyed and mark you as spam. Specifically, you must process that request within 10 business days.

The easier you make things for your recipients, the better. Even if that means to unsubscribe. Remember that unsubscribes are far better than spam complaints.

Design the unsubscribe feature as close to a “one-click” process as possible. Make the opt-out option clear by adding an unsubscribe link at the bottom of every single email you send.

For senders who want a second chance to convince potential unsubscribing users to not do so, keep in mind your unsubscribe process can leave a lasting impression of your business. If you want to survey your unsubscribers, show them the survey right after they have successfully opted out or in the unsubscribe confirmation email, not before.

8. Keep a good text to image ratio

As a general guideline, Mailchimp recommends a ratio of 80 percent text to 20 percent images in a campaign.

However, all spam filters use different criteria for what is a good balance of graphics and text.

Many email providers and desktop email clients actually block images as a standard, so you should strongly consider the risk when sending an all image email.

Spam filters specifically look for those types of image-based emails. Big image files often carry hidden messages that would normally get caught in spam filters . When a spam filter can’t read any real text in an email and only sees an image, it rings an alarm.

If you want to send images, here are some tips to consider:

  • Don’t send image-only emails.
  • Include several lines of text for each image.
  • Keep your image-to-text ratio low.
  • Optimize your images for email by compressing them first. Don’t use super high resolution images or other media with a large file size.
  • Use correct HTML for email. While plain HTML offers the best deliverability, it’s better to style your email using company branding, and including a healthy amount of images.
  • Avoid using too much rich media, like video, and other dynamic scripts like JavaScript or Flash.

9. Don’t sound like a spammer

The more “spam-like” text and phrases your email uses, the less likely it is to end up in the inbox. There are a number of free software solutions to check the “spam score” of an email before you send it, but there are also some basic rules:

Don’t use ALL CAPS

Using all caps and exclamation points may get the attention of your subscribers, but it’s also annoying and will seem spammy to email service providers. Also, only use one exclamation point at a time.

Don’t use lots of colored fonts

According to this report, readers don’t like it when marketers use irregular fonts, sizes or colors.

Stay away from words you’d see in spam (such as free, promo, surprise, winner, guarantee)

There are certain words and phrases that will automatically trigger filters and send your email straight to the spam folder. It doesn’t mean that you can’t use so-called trigger words, but you should use the words that are common to promotion emails as sparingly as possible. Check this list for examples.

Avoid hashbusting, deceptive subject lines and misleading claims:

  • Inserting random characters in the subject line or content to fool spam filters, e.g. “Fre.e. p!riz.e”.
  • Starting the subject line with “Re:” or “Fwd:” to suggest an ongoing communication with the sender.
  • Subject line stating that the recipient has won a prize, while the email cointains conditions that have to be met in order to claim it.
  • Concealing a text message in an image to fool spam filters.

10. Always include a plain-text version of your HTML email

Doing so helps improve your deliverability rates because HTML-only emails are a big red flag for spam filters.

Spam filters check for bad html code. Particularly if it looks like the code was done in Microsoft Word and then thrown into an email. You should use a professional coder or a template provided by your email sending partner.

If you are sending text-only emails, you don’t have to worry about this. Sending only an HTML part is a common cause why email often lands in the spam folder.

So, makes sure your email is sent in the MIME (HTML + plain text) format. Offering both versions makes your emails more reader-friendly.

That way, you can include some branding elements that make your recipients remember your emails. Which helps with engagement.

Making sure to include a text version of your email also covers you in case a recipient cannot view HTML emails.

11. Track your email performance and engagement metrics

The only true way to know if your email program is improving is tracking your email performance and engagement metrics.

Better open rates and stronger click through rates (CTRs) mean better deliverability. So, if you have low open rates, your emails are at higher risk of being flagged as spam.

The following baseline metrics are a good place to start:

  • Spam complaints
  • Open rates
  • Click-through rates

You should look at how many emails are opened and how many are deleted without being opened as a factor in your spam filtering decisions. This is the top reason for inbox placement issues, effecting 26% of email campaigns incorrectly flagged as spam.

If your open rates are starting to go down, review your subject lines and email frequency. Those two variables are likely affecting this metric.

To maximize open rates, send your message at the right times. Perfect your subject lines, segment your list and keep it updated.

In order to increase CTRs, remember to include a call to action in your email. When you include a strong CTA, you create a strong click through rate, improving overall deliverability. More importantly, you’re helping your prospects take action toward becoming a customer.

12. Keep in touch

Sending emails rarely can be more detrimental than sending multiple emails daily. Because your audience might forget about you.

If subscribers don’t recognize the From field, they may delete your message, hurting your “open” ratio. Even worse, they may forget signing up for your list and mark your messages as spam.

Before removing those unengaged subscribers, you can try to win them back with a re-engagement campaign.

To do this, segment your list to create a group of people who haven’t opened your emails in a few weeks or months. Then create a compelling campaign especially for them. Offer them additional discounts, exclusive content and ask for feedback.

Even though quantity has been the most important aspectfor email marketers for years, it’s important to remove old and disengaged users from your list. Senders who practice list management report higher deliverability, higher open rates, and are less likely to see their messages sorted as spam.


Even if you do all of these things and do them correctly, your emails may still end up in the junk folder.

You will, at some point, have email delivery issues.

Email spam filter criteria changes almost daily and can be influenced by things that you have no control over. The two most important things you can do is maintain a clean email list and produce real, meaningful content.

Focus on the content, but don’t forget about presentation in the process. If you send emails that your clients want and continue to evolve and personify, you’ll get into the inbox more often than not.

Always keep in mind that the higher your email engagement, the more likely your email will end up where it is intended and not get caught in spam filters.

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