Why emails go to spam and what to do

Why emails landing in spam (even valid ones)

Have you ever had one of your outgoing emails marked as spam? 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 firstly, let's discuss what the spam filter is and how it works.

What is a spam filter?

It's 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 the message came 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
Using email headers spam filters 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
Spam filter analyzes the body and the subject of the email. Strings, which 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.

We created a list of spam trigger words that can cause your email to be marked as spam.

Click here to expand the list

This isn’t a scam, Earn per week, Mail in order form, Reverses, #1, Easy terms, Maintained, Reverses aging, $$$, Eliminate bad credit, Make $, Risk free, ‘Hidden’ assets, Eliminate debt, Make money, Rolex, 100% free, Email harvest, Marketing, Round the world, 100% Satisfied, Email marketing, Marketing solutions, S 1618, 4U, Expect to earn, Mass email, Safeguard notice, 50% off, Explode your business, Medicine, Sale, Accept credit cards, Extra income, Medium, Sales, Acceptance, F r e e, Meet singles, Sample, Access, Fantastic deal, Member, Satisfaction, Accordingly, Fast cash, Member stuff, Satisfaction guaranteed, Act Now, Fast Viagra delivery, Message contains, Save $, Act Now!, Financial freedom, Message contains disclaimer, Save big money, Act now! Don’t hesitate!, Financially independent, Million, Save up to, Ad, For free, Million dollars, Score with babes, Additional income, For instant access, Miracle, Search engine listings, Addresses on CD, For just $ (some amount), MLM, Search engines, Affordable, For just $xxx, Money, Section 301, All natural, For Only, Money back, See for yourself, All new, For you, Money making, Sent in compliance, Amazing, Form, Month trial offer, Serious cash, Amazing stuff, Free, More Internet Traffic, Serious only, Apply now, Free access, Mortgage, Shopper, Apply Online, Free cell phone, Mortgage rates, Shopping spree, As seen on, Free consultation, Multi level marketing, Sign up free today, Auto email removal, Free consultation, Multi-level marketing, Social security number, Avoid, Free DVD, Name brand, Solution, Avoid bankruptcy, Free gift, Never, Special promotion, Bargain, Free grant money, New customers only, Stainless steel, Be amazed, Free hosting, New domain extensions, Stock alert, Be your own boss, Free info, Nigerian, Stock disclaimer statement, Being a member, Free installation, No age restrictions, Stock pick, Beneficiary, Free Instant, No catch, Stop, Best price, Free investment, No claim forms, Stop snoring, Beverage, Free leads, No cost, Strong buy, Big bucks, Free membership, No credit check, Stuff on sale, Bill 1618, Free money, No disappointment, Subject to cash, Billing address, Free offer, No experience, Subject to credit, Billion, Free preview, No fees, Subscribe, Billion dollars, Free priority mail, No gimmick, Success, Bonus, Free quote, No hidden, Supplies are limited, Brand new pager, Free sample, No inventory, Take action now, Bulk email, Free trial, No investment, Talks about hidden charges, Buy, Free website, No medical exams, Talks about prizes, Buy direct, Freedom, No middleman, Teen, Buying judgements, Friend, No obligation, Tells you it’s an ad, Buying judgments, Full refund, No purchase necessary, Terms and conditions, Cable converter, Get, No questions asked, The best rates, Call, Get it now, No selling, The following form, Call free, Get out of debt, No strings attached, They keep your money – no refund, Call now, Get paid, No-obligation, They’re just giving it away, Calling creditors, Get started now, Not intended, This isn’t junk, Cancel at any time, Gift certificate, Notspam, This isn’t spam, Cannot be combined with any other offer, Give it away, Now, This won’t last, Can’t live without, Giving away, Now only, Thousands, Cards accepted, Great offer, Obligation, Time limited, Cash, Guarantee, Off shore, Trial, Cash bonus, Guaranteed, Offer, Undisclosed recipient, Cashcashcash, Have you been turned down?, Offer expires, University diplomas, Casino, Hello, Once in lifetime, Unlimited, Celebrity, Here, One hundred percent free, Unsecured credit, Cell phone cancer scam, Hidden, One hundred percent guaranteed, Unsecured credit/debt, Cents on the dollar, Hidden assets, One time, Unsecured debt, Certified, Hidden charges, One time mailing, Unsolicited, Chance, Home, Online biz opportunity, Unsubscribe, Cheap, Home based, Online degree, Urgent, Check, Home employment, Online marketing, US dollars, Check or money order, Homebased business, Online pharmacy, Vacation, Claims, Human growth hormone, Only, Vacation offers, Claims not to be selling anything, If only it were that easy, Only $, Valium, Claims to be in accordance with some spam law, Important information regarding, Open, Viagra, Claims to be legal, In accordance with laws, Opportunity, Viagra and other drugs, Clearance, Income, Opt in, Vicodin, Click, Income from home, Order, Visit our website, Click below, Increase sales, Order now, Wants credit card, Click here, Increase traffic, Order shipped by, Warranty, Click to remove, Increase your sales, Order status, We hate spam, Collect, Incredible deal, Order today, We honor all, Collect child support, Info you requested, Orders shipped by, Web traffic, Compare, Information you requested, Outstanding values, Weekend getaway, Compare rates, Instant, Passwords, Weight loss, Compete for your business, Insurance, Pennies a day, What are you waiting for?, Confidentially on all orders, Internet market, Per day, While supplies last, Congratulations, Internet marketing, Per week, While you sleep, Consolidate debt and credit, Investment, Performance, Who really wins?, Consolidate your debt, Investment decision, Phone, Why pay more?, Copy accurately, It’s effective, Please read, Wife, Copy DVDs, It’s effective, Potential earnings, Will not believe your eyes, Cost, Join millions, Pre-approved, Win, Costs, Join millions of Americans, Price, Winner, Credit, Laser printer, Prices, Winner, Credit bureaus, Leave, Print form signature, Winning, Credit card offers, Legal, Print out and fax, Won, Cures baldness, Life, Priority mail, Work at home, Deal, Life Insurance, Prize, Work from home, Dear [email/friend/somebody], Lifetime, Prizes, Xanax, Diagnostics, limited time, Problem, You are a winner!, Dig up dirt on friends, Limited time offer, Produced and sent out, You have been selected, Direct email, Limited time only, Profits, You’re a Winner!, Direct marketing, Loans, Promise you, Your income, Discount, Long distance phone offer, Pure Profits, Do it today, Lose, Quote, Don’t delete, Lose weight, Quotes, Don’t hesitate, Lose weight spam, Real thing, Dormant, Lower interest rate, Refinance, Double your, Lower interest rates, Refinance home, Double your income, Lower monthly payment, Refinanced home, Drastically reduced, Lower your mortgage rate, Removal instructions, Earn, Lowest insurance rates, Remove, Earn $, Lowest Price, Removes wrinkles, Earn extra cash, Luxury car and Reserves the right.

NOTE: This list is not final 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.

There are several things you can do to improve your email delivery Change to Basic requirements for the creation of 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 to 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.
  • If it is possible, avoid different colors of the fonts.

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.

    If you use Namecheap Private Email, you can use this guide to set a DKIM record for your domain.

    If you use Namecheap Shared Hosting, feel free to use this guide to set SPF and DKIM for your domain in cPanel.

  • Check your IP and domain in blacklists. If your IP or domain is blacklisted you should whitelist it or contact your email service provider before sending emails.
  • If you use a new domain name, it is better to warm up the deliverability. Feel free to check this guide.

Other recommendation:

  • Do not purchase email lists. It is 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 and send test emails to them.
  • Send the emails to your clients on a regular basis 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. So what factors contribute to getting false negatives?

  • 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: blocklisted domains, TLDs that are used for sending spam most of all, executable 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 ham.

  • Users may have different opinions about what is considered spam. The definition of spam can be very 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.

    Click here to see the example of an email

    This is an example of Namecheap Newsletter email that we send out to our customers that subscribed to such emails during the signup or in their Namecheap account. This is not a spam email (since users willingly subscribed to it and since such emails contain an "Unsubscribe" button), but may be considered by users as such if they don’t wish to receive these emails.

How to identify spam?

These types of emails are not usually considered as spam by anti-spam systems and therefore can get to your inbox:

  • Direct marketing and newsletter emails that users agreed to (e.g. subscribed to):

  • Transaction emails (e.g. receipts, confirmations, invoices, etc):

  • Auto-renew or "up for renewal" notices (for the services that you willingly purchased):

  • Email bounce notifications:

  • Messages sent to the recipient by mistake.

At the same time, spam can be recognized by its exaggerated promises, sense of urgency and commercial aims. Here are a few things to pay close attention to when checking a potential spam email:

  • Sender
First of all, spammers use long email addresses (using free email services like Gmail, Yahoo, etc) that contain a random collection of letters and numbers. For example, ell45704truiw@gmail.com.
In addition, they may impersonate reputable organizations in order to get access to your data. For example, you may come across fake email addresses that resemble real ones (like, @paypai.com for PayPal or @nelflix.com for Netflix which are not their domains). It is sometimes difficult to spot the difference at once, that’s why it’s very important to look closely at the sender, especially before clicking links in the email or replying to it.

  • Language
Typos, incorrect spelling, obvious grammatical mistakes or resemblance to a poorly translated text from another language are also obvious identifications of a spam email. Valid promotional emails from reputable sources don’t usually contain such mistakes since they take care of their copy.

  • Links
In general, if you receive an unknown email, don’t hurry to click on any links since it can possibly lead to your data leak or you may just download some virus. Spammers can use shortened URLs (like bit.ly, tinyurl.com, tiny.cc, etc) to disguise the links to fraudulent resources that they use to take your personal information, credit card details, passwords, etc. In some cases, these links may lead to downloading a file on your PC. In order to secure yourself it’s recommended not to open the links at all if you’re not sure about the sender or check them in an online links checker.

  • Unrealistic claims
If you get an email offering to purchase something at a ridiculously low price or offering a money reward/prize, you’re most likely looking at a spam message and the best course of action would be to delete the email and report it as spam.

How to report spam?

These are just a few examples of what to be aware of when trying to recognize spam. Keep in mind that even legitimate companies send valid emails that may look spam-like as well. If you’re unsure whether some particular email is valid or malicious, it’s best to ignore it and not interact. Alternatively, you can add the sender, email or subject to the blocklist using Jellyfish. You can do this by following this guide. This will ensure that you, as a user, will not receive emails from the same sender, domain or with the same subject.

Another way to block spam emails on a more global level would be to pass spam emails to Namecheap Support Team to train the Jellyfish system. This is a normal process with anti-spam systems and it ensures that all new spam examples are added to the system’s database and, as a result, such emails (or similar to them) would be rejected in the future for all Jellyfish users.

In order to report spam you will need to do the following:

  1. Ensure that the email is not some kind of a marketing campaign or newsletter that you can opt-out from using the Unsubscribe button;

  2. If you use Namecheap Private Email:

    If you’re sure that the email is indeed a spam one, you can mark it as spam by clicking the Mark as spam button in your Private Email interface. This was the system will learn this preference for your mailbox and no such emails will be delivered to you in the future.

    If you have any questions or would like the system to unlearn the preference, you can just move the necessary email to your Inbox and Jellyfish will learn that such emails are valid and can be delivered to you. If you face any issues with the filtration, please contact our Support Team via Live Chat or Ticket System explaining the matter.

  3. If you use Namecheap Shared Hosting:

    If you’re sure that the email is indeed a spam one, you will need to download it in .eml format. If there are several spam emails, you will need to provide all of them. You can do it following instructions in this guide.

    NOTE: It’s highly recommended that you don’t edit the .eml file or delete anything from it since this is crucial to train the system with the original email in order for the training to be successful. Rest assured that we guarantee 100% confidentiality for such emails and no personal data can leak from the training system. It's strictly for internal use and we highly value our customers' security.

    Then please contact our Support Team via Live Chat or Ticket System providing the file(s) and explaining the matter. They will, in their turn, pass the files to our technical team to ensure that such spam emails are blocked.

That's it!
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