9 Tips to ensure your emails won’t be flagged as spam

Have you ever sent out an email that you never received an answer to for a long time? Chances are that it was most likely flagged as spam and it never arrived in the first place. The truth is that a surprisingly high number of companies and users have probably experienced this at one point through their existence due to the nature of email clients and their spam filters. As a matter of fact, having emails be marked as spam isn’t that uncommon once we get to know the global email landscape:

This is why, even though you might write a very eloquent, well-structured email that is grammatically correct, it could still end up being labeled as spam.

The truth is that the filters and systems can’t really determine your intentions. Despite trying your best to write an informative and legitimate email, spam detection algorithms still flag your email as dangerous. But not to worry, we are here to help! Here are 9 useful tips that you can use in order to improve and optimize your emails so that they don’t get flagged as spam.

Configure SPF, DKIM & PTR records

The SPF record is designed to protect your domain from spammers sending emails on your behalf. While a correctly set up SPF record does not directly relate to your emails’ nature, it can positively influence your image and credibility when it comes to outbound email servers.

If you want to get to know SPF in more detail, you can check out our tutorial on how to create and manage a SPF record.

DKIM (or DomainKeys Identified Mail) is a widely used security standard. Its primary purpose is to ensure that your emails are not modified, changed or altered in transit between your mail server and the recipient.

Creating and maintaining a DKIM record allows you to have better overall security, which will again prevent your emails from being flagged as spam. Similarly to SPF records, we also have a detailed tutorial on how to create a DKIM record, which will walk you through all of the necessary steps so that you can easily complete the setup process.

Finally, we want to discuss PTR records, which are also commonly referred to as RDNS. A PTR record is a specific DNS record type, where a given IP address points to a given domain (host) name.

It is a crucial and inseparable part of creating a secure and credible mail server, which will ultimately reduce the chances of your emails being marked as spam. You can check out our tutorial on how to set a PTR record which will also guide you through each and every step.

Prior technical experience isn’t required as the aforementioned tutorials are very easy to follow. Because of this, you should definitely invest some time and effort into properly setting up all of these records as they will help you gain credibility and allow your emails to arrive without any issues. And while global spam rates are slowly going down, spam messaging is still a large percentage of the total number of emails sent each year:

Make sure your email server’s IP is not blacklisted

In addition to the records that we covered, spam algorithms are also constantly performing checks on your email server’s IP address.

There are literally millions of email addresses, which are all used for different purposes on a daily basis. Due to their sheer volume, spam-detecting patterns have developed email blacklists, which contain addresses that have been previously reported for spam or that have violated some online policies.

Such emails have lost their reputation due to the massive outpour of unwanted emails with inappropriate or irrelevant content.

If your email server’s IP has been identified as such and has been blacklisted, we suggest you try to delist it as quickly as possible, as that can severely damage your credibility and reputation. Start by taking a more in-depth look at the content that you are sending and the people you are reaching out to. Next, make sure to check that your messages aren’t being intercepted and changed prior to arriving at the recipient’s inbox.

There are a few tools to check the reputation of your IP address with one good example being MXToolBox.

Ensure your email server supports TLS authentication

Emails across the Web are sent thanks to the SMTP - Simple Mail Transfer Protocol. By design, this protocol is not encrypted, meaning that information that it transfers can be easily accessed, read and extracted.

What adds the extra layer of encryption to online emails is known as TLS - Transport Level Security. This encryption allows the message to only be viewed by the intended recipient, preventing unauthorized access along the way.

Because of this, you need to ensure that your application, website, CMS and of course - email server, all support TLS authentication. This will improve your overall security and reputation.

Use a custom personal or business email address

We have all received promotional emails coming from free email services like Gmail or Yahoo. While there is nothing wrong with utilizing a free email service, this does damage your credibility.

Instead, if you already have a website or a Web hosting account, create a custom email address using your domain name. This will not only help you build authority and credibility, but can also boost your email engagement and opening rate.

Here’s a very quick tutorial on how to set up a custom email address using cPanel.

1. 1
   Log into cPanel

   Start by visiting yourdomain.com/cpanel or open it up through your web host dashboard. Once there, enter your username and password and log in.
2. 2
   Go to Email Accounts

   In the EMAIL section, click on “Email Accounts.”
3. 3
   Click “Create”

   Select the domain you want to use and enter your desired email username. After that, create a strong password or use cPanel’s password generator.
4. 4
   Set Storage Space (Optional)

   Define how much mailbox space you want (or leave default/unlimited).
5. 5
   Click “Create”

   Done! Your new email address will be ready.

Domain age & reputation

Domain age and reputation are another 2 factors that we want to touch upon. As with SEO, these parameters are crucial when it comes to credibility and authority.

Usually, spam sending domains are relatively new as spam-sending individuals tend to buy a domain name and start sending messages immediately.

This doesn’t mean that you shouldn’t be sending out emails if you have just purchased a domain for your business, website or application. It is just crucial to remember to carefully construct your emails and to set up all of the aforementioned SPF, DKIM and PTR records while also checking that your mail server isn’t present in any of the most popular blacklists online.

Ultimately, combining all of these suggestions will reduce the probability of your emails ending up being inappropriately flagged. But sometimes, even if everything is perfect from a technical standpoint, your emails can still go to your recipients’ spam folder due to the faults of your content, some of which you might not even be aware of.

Avoid letter capitalization

Never use capitalization in the content and the title of your emails. It would be fine to highlight or put an emphasis on a couple of points, but you should mostly try to avoid unnecessary capital letters in your email. This can detract the attention of your readers and email algorithms can mark it as spam.

Additionally, make sure you also use common fonts such as Arial, Verdana, Helvetica, Georgia, Tahoma, Lucida, Trebuchet or Times. This is because some email clients won’t render newer fonts, meaning that your message might appear differently for each user.

Styling & color

Be expressive if necessary, but do try to keep it moderate. The more exclamation points you use at the end of your sentence, the greater the chance of your email not making it to the recipient’s inbox.

Make sure your text is readable. Think of what you want your readers to make out of your email. Avoid using complicated words, terminology and oversaturated structural elements.

Too much highlighted, underlined or bold text is also a no-no. Draw your readers’ attention to the meaning of your content rather than the styling of the text. Make sure you put an accent on the things that really matter.

Do not replace traditional letters with other characters and avoid using too much color when it comes to your text. It would be best to stick to one primary color and color-code everything depending on its importance. Use it sparingly in order to really highlight important elements or sections of your email.

Size and contact relevance

Emails that are larger than 3 MB in size will most likely miss the inbox and go directly to the spam folder. Because of this, you need to keep your email size as low as possible, ideally below 250KB.

In terms of frequency, you should avoid sending emails too often. If you need to alert people of potential problems or issues, then you can make an exception for this rule. However, frequent email sending is seen as spam. If you are sending out a newsletter, make sure to do so only once a week or month, depending on the volume of content that you need to share with your users. Focus on the quality and not on the quantity.

Make sure your email offers an unsubscribe option especially if you are sending out a newsletter or any promotional materials that users have previously subscribed to. If you don’t provide people with such an option, they could report your emails which would damage your overall credibility and reputation. This can really hurt your marketing strategy in the long run especially if you send important information over email.

Next, make sure that you keep your email database updated, you don’t want to be sending out emails to contacts that are no longer relevant.

Also, focus on the subject line of your email. It should be something meaningful and straight to the point. Again, do not capitalize it in an attempt to make the email seem urgent. Avoid placing any call-to-action texts in the email’s subject line.

Ensure that each email you send has properly linked media. Never send an email that only contains links, images or videos. Attaching images is also not considered good practice if you are sending out promotional material. Instead, add the image as a link to its hosted address. Additionally, you should also never use JavaScript elements in your emails as algorithms can find that suspicious.

Language and grammar

Our next tip is to carefully check your text for grammatical and spelling errors, text structure, readability and clarity issues. For example, Grammarly is a great tool that also has a free version which you can use to check that everything is okay prior to sending the email.

Avoid using spam words at all costs. These are high-profile words that are predominantly used in spam emails. If large volumes of such words are detected by the algorithms, the filters will automatically redirect your email to the spam folder. Examples of such words are ‘100%’, ‘#1’, ‘claim now’ and others.

Next up, implement some form of analytics for your email. Grab yourself an email analytics tool and keep track of which emails are successful and which fail to get seen. An email with a low or non-existent open rate can be a sign that it has gone to the spam folder. You can then use this data to construct your emails more efficiently and to debug any issues that you think might have caused the problem. Additionally, such analysis tools can also help improve your email marketing campaigns.

Finally, make sure to check whether your email follows all of the required guidelines and regulations so that you can be confident that it won’t be flagged as spam. A useful tool which you can use to make these checks is Mail Tester.

We hope that this information has been helpful and that our tips can help you figure out exactly why your emails are ending up in the spam folder.