
Why Emails go to Spam and What do you do?

According to statistics, 53% of all sent emails are spam. As a result, spam filters are becoming stricter, and even legitimate emails can end up in the spam folder. There are some steps you can take to ensure that all your emails are being delivered to the inbox on the recipient’s side. But first, let’s discuss what the spam filter is and how it works.
What is a Spam Filter?
A spam filter is a software that identifies and blocks potentially dangerous emails from entering your inbox by using a set of rules and algorithms.
How does the Spam Filter Work?
What a typical spam filter checks for can be divided into three categories:
- Where does the message come from?
Anti-spam organizations have created special network lists, which are called RBLs (Real-time blackhole lists). Spam filter checks such lists for the IP address and the domain name that the message was sent from. If the IP address matches one on the list, the spam score of the message increases.
- Who sent the message?
Use email headers spam filters to check if the email was sent by a spam engine or by a real sender. Every email has a unique ID, but when the spammers send mass emails, they all have the same ID.
- What the message looks like
The spam filter analyzes the body and the subject of the email. Strings, that can be identified as spam are ‘buy now’, ‘lowest prices’, ‘click here’, etc. Also, it looks for flashy HTML such as large fonts, blinking text, bright colors, and so on. A lot of spam filters compare the whole text to the number of suspicious words. So, for example, if your email is long, it will not be identified as spam because of a few suspicious words. Below are examples of spam words:

NOTE: This list is not all and is just an example of some spam patterns. They can constantly change due to the spammers adjusting to the new restrictions on the side of spam filters.
How to Improve Your Email Delivery
There are several things you can do to improve your email delivery Change to Basic requirements for the creation of a valid email:
Valid Sender Information:
- Use a recognizable and legitimate sender email address. Avoid generic or suspicious sender names.
- Ensure that the “From” field accurately represents your organization or brand.
Clear Subject Line:
- Write a subject line that reflects the email’s purpose concisely.
- Avoid misleading or clickbait-style subject lines.
- Do not end a subject with a question mark or space.
- Do not use only uppercase letters.
- Do not use the words like Test/Testing in the subject.
Structured Email Body:
- Organize your email content into paragraphs or sections.
- Use headings, bullet points, and numbered lists to improve readability.
- Do not use the introduction at the beginning of the email.
- Do not use too many special symbols, especially at the beginning or at the end of the sentence.
Signature and Contact Information:
- Include a professional email signature with your name, job title, and contact details.
- A well-formatted signature adds credibility to your email.
Avoid Excessive Links and Attachments:
- Limit the number of hyperlinks in your email.
- Attachments should be relevant and necessary; avoid overloading the email with files.
- Be careful with the images. It is recommended not to send emails with images only. Make sure you have no less than two strings of text in every image and your images are optimized.
- Do not use shortened URLs. Those are often used by spammers to hide their real URLs.
- Avoid some types of attachments like .exe, .zip, .swf. It is okay to use .jpg, .gif, .png and .pdf.
Unsubscribe Option:
- The email should be identified as an ad if that is what you are sending.
- Include an easy-to-find unsubscribe link. Compliance with anti-spam regulations is crucial. Honoring unsubscribe requests builds trust with recipients.
Plain Text Version Alongside HTML:
- Some email clients may not render HTML properly. Including a plain text version ensures accessibility for all recipients.
- Avoid different colors of fonts, if possible.
Domain Configuration:
- Check SPF and DKIM records. Sender Policy Framework (SPF) records allow domain owners to publish a list of IP addresses that are authorized to send emails on their behalf. The goal is to reduce the amount of spam and fraud by making it much harder for malicious senders to disguise their identity. Domain Keys Identified Mail (DKIM) helps you protect your company from email spamming and phishing attempts. It provides a method for validating a domain name identity that is associated with a message through cryptographic authentication.
Other recommendation:
- Do not purchase email lists. It is a common practice to purchase lists of potential clients. However, a lot of email addresses in such lists are not correct and your IP/domain can get blacklisted for mass mailing very fast. It is better to send individual emails to real people.
- Check how your emails are delivered. You can create different email accounts with popular email providers like Google, Yahoo, and so on, then send test emails to them.
- Send the emails to your clients regularly and instruct your recipients on how to whitelist your email address.
Why can Spam be Delivered?
Although anti-spam systems are quite advanced nowadays and should block about 90,9% of spam emails, it’s important to note that no system is perfect enough to block 100% of spam emails for all users (at least for now). When an email containing spam is incorrectly identified as a legit one and is delivered to Inbox it’s called a false negative. For example, links that appear to be of familiar websites, but in fact, lead to phishing websites. What factors contribute to getting false negatives?
- A new spam pattern that is not known to the system yet: Since most anti-spam filters use machine learning technology, they constantly learn on the go, meaning that new spam patterns are added to their database for identifying such emails and blocking them. At the same time, spammers do this as well. When they constantly try to adjust to new realities to deceive anti-spam filters, they create new patterns that systems may not identify at once.
- Subjective content filtering: In some cases, content filtering may get tricky. Where some things are easy to identify, email content is not black and white. Of course, there are known indicators of spam and blocklisted domains. TLDs that are used for sending spam, execute file attachments, or known spam keywords contained in the email. However, content guidelines for spam are always changing, much like our world. That’s what makes it difficult sometimes for anti-spam systems to distinguish whether some email is spam or harmful.
- Users may have different opinions about what is considered spam: The definition of spam can be subjective to most recipients. Some refer to it as simply unwanted communication (including legitimate advertisements that they no longer wish to receive) even if such emails don’t possess spam factors.
That’s it! Feel free to contact us if there is anything we can assist you with.