There is no denying that spam emails are annoying and dangerous, hence the spam filter. But spam filter can become the villain of the story when it catches the legitimate emails you sent your friends, colleagues, or clients and leaves you wondering why you never got a response.

Roughly 1 in 6 emails are detected by spam filters and never reach the inbox. Spam filter works by scanning through emails for phrases and triggers. It can also block senders who are frequently marked as spam or has incorrect sender information. If your email contains at least one spam trigger, it can end up in your recipient’s spam folder.

So, what are the most common reasons your emails end up in the recipient’s spam? Let’s explore!

1. Your Recipient Marked You as Spam

This is the most obvious reason your email goes to the spam box. Even though your email might not be real spam, your recipient might still mark you as spam to declutter their inbox or if they are not interested in hearing from you. It can also be the case that they subscribed to you without realising and opted for the ‘mark as spam’ option rather than unsubscribing.

Whichever the case may be, if your email gets marked as spam frequently, it can trigger the spam filters to flag your email address. It will automatically send future emails to the spam box even for users who haven’t explicitly reported you as spam.

2. Your Subject Lines Contain Spam Triggers

Statistical data shows that ” 69 percent of email recipients report email as spam based solely on the subject line.” While attention-grabbing subject lines raise your recipient’s interest, they also increase the risks of your email ending up in the spam box.

Here are some common subject line practices that can trigger the spam filter:

• The subject starts line with RE even if it’s not a reply
• The subject line contains at least one email spam trigger word
• Includes FW to mislead the recipient
• The subject line consists of a personal message or leading questions
• It consists of an overly sensational claim, even if it is not necessarily misleading

3. The Sender Information is Inaccurate

Incorrect or misleading sender information is a significant reason your emails might end up in spam. FTC states that “Your ‘From,’ ‘To,’ ‘Reply-To,’ and routing information—including the originating domain name and email address—must be accurate and identify the person or business who initiated the message.”

4. You’ve Included Attachments

You should avoid attachments in email unless absolutely necessary for two reasons. First, attachments alert the spam filters as phishers use them to attach phishing links or malware to emails. For example, popular email service providers like Gmail automatically detect password-protected or encrypted files as spam because they cannot scan them for viruses. Second, large attachments can increase the load time unnecessarily, which might motivate the recipient to mark you as spam.

Do not attach it directly to the email if you are using emails to send a large file to a friend or a colleague. Instead, upload your file to a cloud-based storage service and share the link with your recipient.

5. Your Content and Subject Line has Grammatical and Spelling Errors

Non-native cyberattackers often use translators to convert their texts to English — resulting in awkward phrases and grammatical errors. Spam filters are on high alert for grammatical and spelling errors to prevent these scams. When your email subject and content contain typos and errors, it triggers the spam filter. So, proofreading your emails before clicking on the send button can improve your email deliverability.

6. You Haven’t Setup Email Authentication

Email authentications such as DMARC, DKIM, and SPF can improve your email deliverability and reduce the chances of your email ending up in a spam box. These authentication forms allow organizations to claim responsibility for an email and enable the recipient to validate it.

Email authentication improves your brand reputation and automates the spam detection process. Consequently, it increases the receiver’s trust in the sending domain and increases the ISP’s willingness to place their emails in the inbox. Also, major email providers such as Google and Microsoft require DMARC authentication on top of SPF and DIMK for all emails. If your emails are often going to the recipient’s spam, you might want to check email authentication to reach your recipient better.

7. Your Email Design is Poor

Poor email design choices can trigger the spam filter. Emails with the following features have a high chance of ending up in a spam box –

• There is a large image with minimal texts
• It contains broken or glitchy code
• Addressing the recipient by “my friend” or “dear” instead of their name
• Using all caps texts or extreme punctuation marks
• Including strange and unusual fonts
• Providing links to malicious websites
• Not including an unsubscribe button

Nobody wants to clutter their inbox with spam emails. Properly using spam filters can decrease the number of spam you receive, but it can do more harm than good by creating false alarms. This is why it is crucial to take other proactive measures to reduce spam emails, including checking the visibility of your email address on the Internet. Typically, spammers collect email addresses when visible on the web, either on social networking sites or other spam lists. To decrease spam emails and improve email deliverability, you need to check the visibility of your email address.

To check your email address visibility, go to Sniff Email — an online platform dedicated to finding out if your email address exists on the Internet. Enter your email address in the search field and click fetch to find out if your email address exists on the web within a few seconds. Based on the results, you can take appropriate action to remove it.