What does a SpamAssassin 'try it' message from mail-tester.com mean?
Michael Ko
Co-founder & CEO, Suped
Published 17 May 2025
Updated 17 Aug 2025
6 min read
When you test your email deliverability using platforms like mail-tester.com, you might encounter a SpamAssassin message indicating a 'try it' rule. This specific message often causes confusion because the phrase 'try it' might not be explicitly present in your email's content or links. Instead, it points to a pattern that SpamAssassin identifies as potentially suspicious, suggesting your email might resemble characteristics often found in spam.
Understanding these nuanced alerts is crucial for optimizing your email campaigns. SpamAssassin is an open-source anti-spam platform that assigns a score to each email based on various tests. A higher score increases the likelihood of your email being marked as spam. While SpamAssassin is widely used by mail servers, interpreting its granular feedback, like the 'try it' message, requires insight into its rule-based detection system.
The role of SpamAssassin in email filtering
SpamAssassin functions by running numerous tests on incoming emails, checking everything from headers and content to authentication records. Each test, if triggered, adds a certain number of points to the email's overall spam score. If the total score exceeds a predefined threshold, the email is flagged as spam and may be delivered to the junk folder or rejected outright. This threshold can vary significantly between different email providers and individual mail server configurations. You can learn more about Apache SpamAssassin directly from its official project website.
While SpamAssassin remains a relevant tool, especially for smaller mail servers and individual users, its scoring should be considered as one piece of a larger deliverability puzzle. Modern inbox providers like Gmail and Outlook employ far more sophisticated, behavioral-based filtering algorithms. These algorithms factor in user engagement, sender reputation, and complex machine learning models, which often outweigh traditional content-based spam scores. Even so, understanding SpamAssassin's relevance for modern email deliverability can still provide valuable insights into potential issues.
For example, mail-tester.com's FAQ highlights that SpamAssassin is a vanilla implementation, meaning it uses default rules without custom adjustments. This can sometimes lead to false positives where legitimate emails are flagged simply because their content or structure incidentally matches a problematic pattern. This is why a holistic approach to email deliverability, encompassing authentication, sender reputation, and engagement, is essential.
Deciphering the 'try it' rule and its implications
The 'try it' message from SpamAssassin, often specifically tied to the rule URI_TRY_3LD, indicates that one of the URLs in your email has a suspicious hostname structure. It does not mean the exact phrase 'try it' is found in your email. Instead, it means the URL contains specific keywords such as 'try', 'start', 'get', 'save', 'check', 'act', 'compare', 'join', 'learn', or 'request' at the beginning of a third-level domain (e.g., try.example.com). This pattern is frequently abused by spammers to create deceptive links.
This rule targets a common spammer tactic: using subdomains with generic, action-oriented words to make phishing or malicious links appear legitimate. For instance, a link like check.yourbank.example.com could be flagged even if yourbank.example.com is legitimate, simply because the 'check' subdomain matches the rule's suspicious pattern. It is an example of how SpamAssassin rules affect email deliverability.
SpamAssassin's content-based focus
Rule-based scoring: Primarily analyzes email content, headers, and links against predefined rules and patterns.
Lexical analysis: Flags suspicious words or phrases, often leading to false positives for legitimate marketing emails.
URL patterns: Identifies URLs with unusual structures or keywords that mimic phishing attempts.
Modern ISP deliverability factors
Sender reputation: Based on sending volume, bounce rates, spam complaint rates, and engagement.
Authentication: Strong enforcement of SPF, DKIM, and DMARC for domain validation.
User engagement: Opens, clicks, replies, and emails moved to inbox significantly influence placement.
Impact on email deliverability
A 'try it' message, or any other negative score from SpamAssassin, indicates areas where your email might be perceived as spam by certain filtering systems. While a perfect mail-tester.com score is desirable, a minor deduction from a rule like 'try it' does not automatically mean your emails will go to spam. Many emails with scores slightly above zero still reach the inbox. The key is the cumulative score and how much weight a particular mail server gives to SpamAssassin.
However, ignoring these warnings completely is not advisable. A problematic pattern, even if minor, could contribute to a higher overall spam score when combined with other issues. This is especially true if you are sending to recipients whose mail servers rely heavily on SpamAssassin. Furthermore, these patterns often mirror broader issues that might be flagged by other, more advanced spam filters. You can check if your emails are going to spam using our guide to troubleshooting deliverability.
Rule Category
Description
Potential Impact
URI Rules
Flags suspicious URLs, including unusual structures or deceptive wording (like 'try it' patterns). Hexadecimal sequence errors are another example.
Can add points if URLs resemble phishing or deceptive links. Consider subdomain alignment.
Authentication Rules
Checks for valid SPF, DKIM, and DMARC records. Failures indicate potential spoofing.
Significant negative impact if authentication fails. Strong indicators of spam for many filters.
Content/Header Rules
Identifies suspicious keywords, unusual formatting, or missing/malformed headers. For instance, FONT_INVIS_MSGID and MIME_NO_TEXT.
Can increase score if content mimics typical spam emails or is poorly constructed.
Blacklist Checks
Verifies if the sending IP or domain is listed on common public blocklists (blacklists).
Often results in immediate rejection or spam folder delivery. Using a blocklist checker is recommended.
Strategies for improving your score
To reduce the chances of triggering rules like 'URI_TRY_3LD' or other SpamAssassin warnings, focus on clean, clear, and authentic email practices. Ensure that all your links use standard, readable subdomains and avoid generic, action-oriented prefixes if they are not genuinely part of your brand's usual URL structure. It is important to fix email deliverability issues proactively.
Beyond specific URL patterns, robust email authentication is paramount. Make sure your SPF, DKIM, and DMARC records are correctly configured and aligned. Authentication failures can significantly increase your spam score and lead to your emails being rejected or blocklisted (blacklisted). Troubleshooting Gmail spam issues often starts here.
Best practices for email content and links
Use clear URLs: Avoid generic or action-oriented subdomains that might trigger spam rules.
Ensure authentication: Properly configure SPF, DKIM, and DMARC to build sender trust.
Maintain engagement: Focus on sending relevant content to engaged subscribers to improve sender reputation.
Beyond authentication and URL patterns, consistently monitor your sender reputation and adjust your sending practices based on feedback from email deliverability tests and postmaster tools. A strong sender reputation is your best defense against spam filtering, even from systems like SpamAssassin. Remember that effective email marketing is a continuous process of optimization and adaptation to evolving email ecosystem requirements.
Views from the trenches
Best practices
Always prioritize sender reputation and authentic email practices over solely focusing on individual SpamAssassin scores.
Regularly monitor your email authentication records (SPF, DKIM, DMARC) to ensure they are correctly configured and aligned.
Segment your audience and personalize content to improve engagement metrics, which are crucial for modern deliverability.
Keep your email list clean by removing inactive subscribers and managing bounces to avoid hitting spam traps.
Common pitfalls
Over-optimizing content for SpamAssassin rules and neglecting broader deliverability factors like sender reputation.
Using generic, action-oriented words in subdomains that can trigger specific spam rules like 'URI_TRY_3LD'.
Failing to implement or properly configure email authentication protocols (SPF, DKIM, DMARC).
Not regularly checking blocklists (blacklists) or analyzing bounce messages for hidden issues.
Expert tips
Focus on domain reputation and user engagement, as these are the primary factors for major inbox providers today.
Ensure consistency in your email sending patterns and volume to build a reliable sender profile.
Invest in DMARC reporting to get comprehensive feedback on authentication failures and potential spoofing attempts.
Periodically review your email content for any elements that might be unnecessarily complex or obscure.
Expert view
Expert from Email Geeks says that the 'try it' rule often means SpamAssassin thinks a URL looks suspicious based on its patterns of dodgy URIs.
2023-07-18 - Email Geeks
Marketer view
Marketer from Email Geeks says that the 'try it' message is a generic rule name, indicating the URL matches a complex regex, not that the exact phrase 'try it' is present.
2023-07-18 - Email Geeks
Moving beyond the 'try it' warning
The SpamAssassin 'try it' message from mail-tester.com is a specific alert, pointing to a suspicious URL pattern in your email, rather than a literal phrase. While SpamAssassin plays a role in identifying spam, modern email deliverability relies more heavily on comprehensive sender reputation, strong email authentication, and positive user engagement.
By understanding these nuances and implementing best practices like ensuring clean URLs, robust authentication, and consistent list hygiene, you can significantly improve your inbox placement. Focus on building trust with both mailbox providers and your subscribers, ensuring your messages consistently land where they belong: in the inbox.
Gmail and 
Outlook employ far more sophisticated, behavioral-based filtering algorithms. These algorithms factor in user engagement, sender reputation, and complex machine learning models, which often outweigh traditional content-based spam scores. Even so, understanding SpamAssassin's relevance for modern email deliverability can still provide valuable insights into potential issues.
