How do spamassassin rules affect email deliverability?
Summary
What email marketers say12Marketer opinions
Email marketer from HubSpot recommends testing emails with tools like GlockApps before sending them to a large audience. These tools simulate different spam filters, including SpamAssassin, and provide insights into potential deliverability issues. Testing helps identify and fix problems before they impact the email campaign.
Email marketer from GlockApps shares that using a dedicated IP address can improve sender reputation and email deliverability. With a dedicated IP, the sender is not sharing the IP with other senders who might engage in spammy practices. A good IP reputation helps bypass spam filters like SpamAssassin.
Email marketer from Campaign Monitor explains that sender reputation is a key factor in email deliverability. Maintaining a good sender reputation involves consistently sending valuable content, avoiding spam complaints, and properly authenticating emails. SpamAssassin and other filters heavily rely on sender reputation to determine if an email should be delivered.
Email marketer from Reddit explains that using URL shorteners can negatively impact email deliverability. SpamAssassin may flag emails with shortened URLs as suspicious. It is best to use full, transparent URLs.
Email marketer from ActiveCampaign explains that maintaining good list hygiene is critical for email deliverability. Regularly removing inactive subscribers and handling bounces and unsubscribes promptly helps improve sender reputation and reduces the chances of emails being flagged as spam by SpamAssassin and other filters.
Email marketer from Litmus explains that poorly coded HTML emails can trigger spam filters like SpamAssassin. Clean, well-structured HTML is essential for improving deliverability. Avoid excessive use of tables, inline CSS, and other coding practices that can be flagged as suspicious.
Email marketer from Email Geeks shares when in doubt about TLDs, check the Spamhaus list of most abused TLDs. If a TLD is listed there, it should be considered as having a potential impact on deliverability.
Email marketer from Email Marketing Forum suggests avoiding excessive use of all caps and exclamation points in email subjects and body. SpamAssassin often flags emails with these characteristics as spam.
Email marketer from Mailjet explains that proper email authentication (SPF, DKIM, DMARC) is crucial for improving email deliverability. These protocols help verify that an email is genuinely sent from the claimed domain, reducing the chances of being flagged as spam by SpamAssassin and other filters.
Marketer from Email Geeks explains that triggering custom spamassassin rules doesn't necessarily mean serious blocking by mainstream mailbox providers, as they use more holistic approaches. Also that it's useful to see what a stock spamassassin thinks of your email to help with self hosted domains.
Email marketer from SendPulse shares that using 'spammy' words in your email content can trigger SpamAssassin and negatively affect deliverability. They provide a list of common spam trigger words to avoid, and suggest focusing on clear, concise, and value-driven content.
Email marketer from Neil Patel explains that understanding spam filters is crucial for email deliverability. He highlights that spam filters, like SpamAssassin, use various rules to identify spam, and avoiding these triggers is vital to ensure emails reach the inbox. He suggests focusing on content, sender reputation, and authentication to bypass spam filters.
What the experts say3Expert opinions
Expert from Word to the Wise emphasizes the impact of sender reputation on email deliverability. They note that SpamAssassin and other filters use sender reputation as a key factor in determining whether to deliver an email. Improving sender reputation requires consistent email practices, such as sending relevant content, avoiding high bounce rates, and implementing feedback loops.
Expert from Spamresource explains that SpamAssassin evaluates various email attributes to determine its score. Factors like poor HTML coding, use of spam trigger words, broken links, and lack of proper authentication records (SPF, DKIM) can increase the SpamAssassin score, negatively impacting deliverability. Addressing these factors is crucial to improve inbox placement.
Expert from Email Geeks explains the 0.5 KAM_NUMSUBJECT rule is a low-scoring spamassassin rule and suggests reconsidering potentially dodgy-looking subject line formats, such as "your invoice #12345" which is often associated with PDF malware. He also adds that while most spam filtering relies on mail stream and content reputation, SpamAssassin rules can be a trigger to take a second look at email practices.
What the documentation says5Technical articles
Documentation from DKIM.org states that DKIM (DomainKeys Identified Mail) helps improve email deliverability by providing a digital signature that verifies the sender's identity. This makes it more difficult for spammers to forge emails and improves sender reputation, reducing the likelihood of emails being flagged by spam filters.
Documentation from MXToolbox explains that being blacklisted can severely impact email deliverability. SpamAssassin and other spam filters often consult blacklists to identify spam sources. MXToolbox provides tools to check if a domain or IP address is on any major blacklists.
Documentation from SpamAssassin Wiki explains that SpamAssassin uses a rule-based scoring system. Each rule that matches an email adds a certain score. If the total score exceeds a defined threshold, the email is marked as spam. The documentation details how different rules contribute to the overall score and how administrators can customize these rules.
Documentation from Spamhaus highlights the importance of sender reputation in email deliverability. Spam filters, including SpamAssassin, often use reputation data to assess the trustworthiness of a sender. Maintaining a good sender reputation is essential for bypassing spam filters.
Documentation from RFC specifies that Sender Policy Framework (SPF) is an email authentication method designed to prevent spammers from forging the 'from' address in emails. SPF records help receiving mail servers verify that emails claiming to be from a specific domain are authorized by that domain, improving deliverability and reducing the chances of emails being flagged as spam.