How to Avoid Spam Filters in Email Marketing

Date: 2024-03-14 | Time of reading: 11 minutes (2128 words)

Marketers are constantly challenged with avoiding spam filters, dealing with words and phrases that trigger spam detection, and ensuring that emails land in recipients' inboxes rather than spam folders. While it can be a nerve-wracking and tiresome task, taking a step back can help determine the best course of action to ensure email campaigns don't end up in spam folders.

In this article, we'll explore where to start to ensure emails reach recipients. First, we'll define email spam, discuss tactics to avoid emails being marked as spam, identify words and phrases to avoid, and finally, examine how to test spam filters.

What is spam and unwanted email

Spam, or unwanted email, refers to inappropriate and unsolicited emails that are sent en masse to a large number of random recipients.

There's a distinction between spam emails and spam folders, which serve as repositories for anything deemed spam by email clients, internet service providers, and recipients themselves. Not everything in the spam folder is harmful; in fact, the majority of its contents are not. Therefore, it's important to adhere to proper behavior to prevent your emails from being marked as spam.

Malicious content is almost entirely blocked by internet service providers, which have significantly improved spam filters in recent years. This improvement is due to the introduction of anti-spam laws (GDPR, CAN-SPAM, CASL, and others) that protect recipient data.

Today, it's easier than ever for users to mark an email as spam thanks to increasingly sophisticated interfaces of email clients. With just one click, all future messages from a specific sender can be marked as unwanted, diverting them to the corresponding folder.

Gmail's features make it easy for people to unsubscribe from newsletters they don't want to receive

Definitions of email delivery related terms

In the Email Delivery Status Report for 2023, 36.2% of respondents stated that improving email delivery was their main goal. The reason is that there is no point in spending time creating great content if it will never be read.

But before delving into ways to improve delivery, it's important to start with some key terms on this topic.

What is a spam filter

When an email passes through a server, it undergoes multiple checks. Internet service providers (such as Gmail, Yahoo) have implemented filters to ensure that spam and malicious email do not reach recipients' inboxes.

It's important to remember that deliverability and delivery are different things. Both terms sound very similar, but they should not be confused.

Deliverability refers to the set of methods, rules, and recommendations available to the sender to ensure that their emails are most likely to land in recipients' inboxes rather than in spam folders.

What is a spam trap

A spam trap is an email address that is not used for communication and should never receive emails. If email campaigns are sent to this address, they are automatically flagged as spam, significantly lowering the sender's reputation with internet service providers.

What is a soft bounce

A soft bounce occurs when an email is returned to the sender due to temporary delivery issues: if the recipient's mailbox is full, the server is unavailable, or the message is too large.

What is a hard bounce?

A hard bounce occurs when an email is returned to the sender because it cannot be delivered under any circumstances: the address is entered incorrectly or is fake because the subscriber was interested in receiving a bonus upon registration, not a newsletter.

Therefore, it is always useful to set up double opt-in - double subscription confirmation.

What is a hard bounce

Therefore, it is always useful to set up double opt-in — double subscription confirmation.

How to deliver email to the inbox, not the spam folder

How to prevent email from going to the spam folder

You can create the most magnificent marketing email campaign in the world, but if it doesn't land in the inbox, no one will read it. All efforts will be in vain.

But there are several excellent pieces of advice to follow to improve sender reputation and deliverability.

Sender address

Avoid using free email addresses based on web services (e.g., Gmail) for sender addresses.
Use your own email address with a domain associated with your website. Then you can set up DKIM and SPF, allowing recipient servers to authenticate the mail.
Make sure your website is active and functional. Sending emails from an address associated with an inactive or empty website will raise suspicion among internet providers.

Contact lists

Do not buy or copy contact lists from third parties. Such lists often contain many spam traps and low-quality email contacts, which violates sending policies.
Create quality contact lists by collecting email addresses through subscription confirmation on your website. Double opt-in is recommended to confirm the subscription, preventing mistyped or fake email addresses. This also confirms that the user agrees to receive your emails.
Regularly update and clean your contact lists. Monitor data and remove old addresses that do not interact with emails or are blocked. Focus on people interested in your mailings.

Content of the email

Do not WRITE ALL WORDS IN CAPS in the subject line or in the body of the email.
Do not use spam words: "Free," "Sale," "Money," "Hot offer," etc.
The subject line should be 35-50 characters. The longer it is, the more likely it is to be marked as spam.
Send content that subscribers have signed up for and are expecting. If you send inappropriate content, subscribers will mark you as a spammer. The more people open your emails, the better your reputation.
Send emails regularly.

Tips on how to send mass emails and avoid spam

Mass emails in the inbox, unfortunately, often annoy, especially if you do not monitor your lists, campaigns, and sending process.

Our current tips will help you ensure the delivery of your emails.

Monitor your contact list

When it comes to email campaigns, we start with the contact list.

The first thing to look at when experiencing delivery issues is the email address lists. Then you need to determine:

The origin of the contacts.
Whether they interact with the content, and if so, how.
How often do you clean up your contact list.

Under no circumstances should you buy contact lists or download them from the internet. This will not only reduce the deliverability of your emails. In a world where people are increasingly concerned about data privacy and where legislation is becoming stricter, the best practice remains natural list building of email addresses.

Next, pay attention to how users interact with the content. What are the open rates, bounce rates, and blocks? If you don't monitor this, the numbers can steadily increase, and as a result, deliverability will decrease.

Although users who don't want to receive emails usually unsubscribe, they may also ignore emails or mark them as spam. Email providers (such as Gmail or Outlook) will also start filtering your emails and sending them to spam on behalf of their users. As a result, the responsibility lies with you: you need to clean email lists and maintain growth in open rates and deliverability.

Remember: brands that maintain list cleanliness see an increase not only in open rates but also in the overall number of email openings due to higher-quality deliverability.

Use email authentication with SPF, DKIM, and DMARC

Trust and permission play a key role in a successful email marketing strategy, making this channel one of the most powerful in sales.

To avoid ending up in spam, you need to assure email providers like Gmail, Yahoo, or Outlook that you are indeed you.

You don't need to fake an ID for this. It's a bit more complicated.

Here are a few points to consider to earn trust for your email, prove your identity, and pass spam filters:

SPF (Sender Policy Framework) is an email validation protocol designed to detect and block forged email senders. It has a mechanism that allows receiving mail exchangers to verify that incoming mail from a domain actually originates from the IP address authorized by the administrators of that domain.
DKIM (DomainKeys Identified Mail) is an email authentication method designed to detect forged emails. It is a way to sign and verify email messages at the MTA level using public and private keys. Public keys are published in DNS TXT records. DKIM authenticates the source and its content.
DMARC (Domain-Based Message Authentication Reporting and Conformance) is an email validation system that detects and prevents email spoofing. It tackles phenomena such as phishing, spoofed sender spam, where emails appear to come from a legitimate organization at first glance.

How spam words trigger spam filters

Over the past few years, internet providers have become more resourceful and have moved away from traditional spam triggers.

Now they learn from our interaction process with messages in our inbox. From this information, they determine whether to send an email to spam or deliver it to the inbox.

And knowing this, how do you decide what to write in the email subject line and what not to write in it?

Words can confuse users, leading to more spam complaints than usual. And such complaints, along with low recipient engagement with the email, negatively impact the sender's reputation and, ultimately, affect the deliverability of future mailings.

How many times have you seen the word "Free" in an email subject line? And how many of them actually had free offers? Most likely, very few. And that explains why, when you see "Free" in your inbox, you just roll your eyes ironically in response to an attempt to entice you to open a deceptive email.

If people still open the email and see that there is nothing free there, senders receive a high frequency of complaints: sending emails to spam or unsubscribes, which will affect the sender's reputation.

Below are some common terms on the subject of spam, so you don't use trigger words and aren't mistaken for spammers or, worse, phishers.

Money transfer

"Money transfer" are favorite words of phishers. If you see this in the subject line, you are likely being lured to open the email. Make sure the sender's address is correct, then there's a chance the email is genuine. The address billing@ex-ample.com and the address billing@example.com are different email addresses. Scammers try to take advantage of our carelessness.

PayPal, Visa/MasterCard, or the name of any other bank

This is another case where a good name can be used for phishing.

Scammers often try to impersonate financial institutions and send emails with similar corporate colors and style. But the links lead to mirror sites that resemble the real company websites.

Consumers should check the sender's address and domain name. And marketers should use DKIM, SPF, and other authentication tools to prevent fake emails from harming the company's reputation.

Lottery, gift, prize

These are always seen in the spam folder. Hundreds of thousands of emails are sent to people with subject lines claiming they have just won a big prize or that they have been selected for a lottery they never entered. You have to be very naive to believe this, but scammers still send them out by the millions because it's quick and easy.

Urgent, please help

For many years, variations of the "damsel in distress" scheme have appeared, where phishers pretend to be wealthy individuals from a distant country who, being pursued by criminals, are forced to flee to a safe place.

For some reason, they choose you as the sole caretaker of all their money and promise a large reward for helping them open an account at a specific bank so they can transfer their funds. Such spammers have become the subject of many jokes, so avoid using similar words to avoid being among them.

Casino, free spins, deposit bonus

Spammers associated with gambling often send campaigns promising high earnings, free entry, or doubling deposits. If the links do not lead to a well-known site, such emails are likely to end up in the spam folder.

Source: Mailjet