mail-tester.com is a tool that helps you check whether an email message is likely to be accepted by receiving mail servers. It analyzes both the message itself and the technical configuration behind the domain used for sending email.
This can be useful when your emails are reaching spam folders, being rejected, or when you want to check whether your mail configuration is correct before sending important messages.
Table of Contents
What mail-tester.com checks
mail-tester.com gives you a temporary test email address. After you send a message to that address, the tool analyzes the email and generates a report.
The report may include checks related to:
- SPF records
- DKIM signatures
- DMARC policy
- server reputation
- message formatting
- links included in the email
- content that may look suspicious to spam filters
- whether the sending server is listed on common blocklists
The result is shown as a score from 0 to 10. A higher score usually means that the message and mail configuration are better aligned with standard deliverability practices.
A good score does not guarantee that every message will reach the inbox. Email delivery also depends on the recipient’s mail provider, previous sending reputation, message history, and user-level filtering.
How to use mail-tester.com
- Open mail-tester.com in your browser.
- Copy the temporary email address shown on the page.
- Open the mailbox or application you want to test.
- Create a normal email message.
- Send the message to the temporary mail-tester.com address.
- Return to mail-tester.com.
- Click the button to check the result.
- Review the score and the report sections.
For the most useful result, send a real example of the type of message you normally send. If you are testing a newsletter, send the newsletter format. If you are testing a normal business message, send a normal business email.
How to interpret the score
mail-tester.com uses a 0 to 10 score.
A score close to 10 usually means that the technical setup and message structure are in good condition. A lower score means that the report found issues that may affect deliverability.
Common causes of a lower score include missing SPF, DKIM, or DMARC configuration, poor message formatting, suspicious links, or the sending server appearing on a blocklist.
The score should be treated as guidance, not as a final delivery guarantee. It helps identify problems, but it cannot fully predict how Gmail, Outlook, Yahoo, or another provider will handle every message.
Important report sections
SPF
SPF is a DNS record that tells receiving servers which mail servers are allowed to send email for your domain.
If SPF is missing or incorrect, receiving servers may treat the message as less trustworthy.
DKIM
DKIM adds a digital signature to outgoing messages. This helps receiving servers confirm that the message was not changed after it was sent and that it is connected to the sending domain.
If DKIM fails, the issue is usually related to mail server configuration or DNS records.
DMARC
DMARC tells receiving servers what to do when SPF or DKIM checks fail. It also helps protect the domain from unauthorized sending.
If DMARC is missing, mail can still work, but the domain has less protection against spoofing and phishing attempts.
Blocklists
A blocklist result means that the sending server’s IP address or domain may have been reported for suspicious email activity.
This can affect delivery, especially when sending to strict providers. Some listings are temporary, while others may require investigation.
Message content
mail-tester.com may also check the message body, links, formatting, and headers.
Messages with broken HTML, too many links, suspicious wording, or missing plain-text versions may receive a lower score. This is especially relevant for newsletters and automated messages.
What to do if the score is low
Start with the technical issues first. SPF, DKIM, DMARC, and blocklist problems usually have a stronger impact than small content suggestions.
If the report mentions DNS records, check whether the domain has the correct mail-related records configured. DNS changes may take time to propagate, so results may not change immediately after editing records.
If the report mentions message content, adjust the email and test again. You may need to simplify the formatting, reduce the number of links, or correct broken HTML.
If the report mentions a blocklist, contact your hosting or email provider so the sending server can be checked.
What is normal
It is normal for the score to change when you test different messages.
A plain business email may receive a different result than a newsletter, even if both are sent from the same mailbox. This happens because the tool checks both server configuration and message content.
It is also normal for changes to DNS records not to appear immediately. DNS propagation can take some time depending on the domain and previous record settings.
When to contact support
Contact support if mail-tester.com reports issues related to SPF, DKIM, DMARC, server configuration, or blocklists and you are not sure how to correct them.
When contacting support, include the mail-tester.com report or a screenshot of the relevant result. This helps identify whether the issue is related to DNS configuration, mail server settings, or the message itself.
Summary
mail-tester.com is a useful tool for checking the technical and content quality of outgoing email messages. It helps identify common issues that can affect deliverability, such as missing DNS records, failed authentication, blocklist listings, or problematic message formatting.
The result should be used as a guide. A high score improves confidence in the setup, but final delivery still depends on the recipient’s mail provider and filtering rules.