No Spam - best practices: how not to fall into spam? Part 1 of 4
February 11, 2025
In this article, we will present the most important rules that, if followed, will avoid the problem of falling into spam emails. Among other things, you will learn how to correctly configure mail and how to avoid mistakes that can lower the reputation of your domain.
1. Correctly configure mail authentication
One of the key reasons why messages end up in spam is incorrect settings of authentication protocols. These are what help mail servers recognize whether an email is coming from a trusted source.
1.1 SPF record
SPF (Sender Policy Framework) is a mechanism that allows you to determine which servers can send messages on behalf of your domain.
Failure to properly configure the SPF record can cause the recipient to consider your message suspicious. Setting up SPF is therefore absolutely crucial for your emails to be properly verified.
1.2 DKIM protocol
DKIM (DomainKeys Identified Mail) is another authentication element that adds a digital cryptographic signature to a message. Its purpose is to confirm that the message has not been modified during transmission.
DKIM provides additional security and lets receiving servers know that your domain is actually sending these messages.
1.3 DMARC - additional protection
DMARC (Domain-based Message Authentication, Reporting, and Conformance) is a policy that determines how mail servers should treat emails that fail SPF or DKIM verification. Correct DMARC configuration provides additional layers of protection and ensures that messages are treated as secure.
In summary: SPF, DKIM and DMARC are the three pillars of effective spam protection. Configuring them correctly is a must if you want to avoid message deliverability problems.
2. Take care of domain and IP address reputation
Mail servers monitor the reputation of domains and IP addresses of senders. If your domain gets blacklisted, your emails will automatically be marked as spam.
Factors affecting reputation:
- Sending a large number of emails in a short period of time.
- A large number of spam complaints.
- Use of the domain by hackers to send phishing emails.
To avoid problems:
- Regularly monitor your domain and IP reputation.
- Take care of your mail and server security.
- Use strong passwords and two-factor authentication.
3. Optimize message content
It's not just the technical aspects that matter. The content of your e-mail also affects whether it will go to spam. Here are the key rules:
3.1 Avoid excessive graphics
Spam filtering may be suspicious of messages that consist mainly of images. The recommended text-to-image ratio is 60/40.
3.2 Don't use “banned” words
Some phrases such as “% free”, “click here”, “guaranteed profit” can make your message be marked as spam.
3.3 A well-formatted e-mail signature
Every professional message should include a properly formatted email footer with sender information, an unsubscribe link and an HTML email signature.
You can read more about how to create a professional signature here.
Summary
If you want to avoid spam problems, follow these tips:
- Correctly configure SPF, DKIM and DMARC - these are the key to effective authentication of your messages.
- Take care of your domain and IP address reputation - monitor them regularly and avoid spamming.
- Optimize the content of your emails - don't overdo the graphics, avoid spam keywords and use a proper email signature.
These practices will make your messages more likely to reach the recipient instead of the “spam” folder.