What are the challenges and legal risks of maintaining a public spammer list, and what tools and methods do ESPs use to manage spammers?

Email marketer from Talos Intelligence explains that they maintain a comprehensive reputation system that ESPs can use to evaluate senders. This system considers factors like email volume, spam complaints, and malware detection.

Email marketer from Validity explains that ESPs employ data validation techniques to identify and remove invalid or risky email addresses from their lists. This reduces bounce rates and improves overall deliverability.

Email marketer from Email Marketing Forum explains that ESPs use honeypots (fake email addresses) to identify spammers. Sending emails to these addresses is a strong indicator of spamming activity.

Email marketer from StackExchange shares that ESPs use feedback loops with major email providers to receive reports of spam complaints. This helps them identify and take action against spammers.

Email marketer from CircleID shares that operating a blacklist involves legal risks, including potential lawsuits from those listed. Maintaining accuracy and transparency is crucial to mitigate these risks. Defamation laws and anti-trust regulations are the primary concerns.

Email marketer from Litmus shares that tracking user consent is crucial for legal compliance and maintaining a good sending reputation. ESPs must ensure they have explicit permission to send emails to recipients.

Email marketer from EmailVendorSelection.com explains that a key challenge of maintaining a spammer list is keeping it accurate and up-to-date. Spammers constantly change tactics, making it difficult to maintain a comprehensive and reliable list.

Email marketer from Mailjet explains that using dedicated IP addresses allows senders to build their own reputation, separate from shared IP pools. This gives them more control over their deliverability.

Email marketer from Reddit shares that ESPs often use domain reputation services to assess the trustworthiness of sending domains. Poor reputation can lead to emails being blocked or sent to the spam folder.

Expert from Email Geeks says eHawk does something similar to a spammer list, and Steve Atkins concurs that eHawk is the closest thing out there.

Expert from Email Geeks shares that even with technical solutions like blinding or hashed searches, the risk of lawsuits remains high when creating a public spammer list.

Expert from Email Geeks explains that the most egregious spammers can adapt more quickly than a company can update its list, which is why search engines no longer manually curate their indexes.

Expert from Email Geeks explains that ROKSO and eHAWK are tools that ESPs use to manage spammers, along with internal vetting and private discussions.

Expert from Word to the Wise shares that common techniques to identify spammers involve tracking sending patterns, analyzing content for spam-like characteristics, and using honeypots to catch unsolicited emails. Collaboration between ESPs and the use of shared blacklists are also important.

Expert from Email Geeks says that to effectively track spammers, one needs to query on bank accounts, phone numbers, physical addresses, and people’s names, which raises privacy concerns and legal risks.

Expert from Spam Resource explains that there are no specific laws that explicitly regulate spammer lists themselves, but general laws about defamation, antitrust, and data protection can apply. Operating a blacklist requires careful consideration of these legal frameworks.

Expert from Word to the Wise explains that reputation systems are built upon multiple data points including user complaints, spam traps and infrastructure monitoring. Using this information senders are then assigned a reputation score used to determine if future emails should be delivered.

Expert from Email Geeks explains that legally, maintaining a spammer list carries the same level of risk and complexity as running a credit agency, which is expensive and not something ESPs are generally willing to invest in.

Expert from Email Geeks states that spammers can be identified by names, domains, credit cards, phone numbers, and company IDs.

Documentation from Surbl.org explains that SURBL (Spam URI Real-time Blocklist) detects websites appearing in spam messages. It is used by mail systems to filter spam based on malicious URLs.

Documentation from Google Postmaster Tools explains that Google provides tools for senders to monitor their reputation. This includes metrics like spam rate and IP reputation, which help senders identify and address issues affecting deliverability.

Documentation from Cloudflare explains that bot management tools are used to identify and block malicious bots that may be used for spamming. They use various techniques, including behavioral analysis and challenge-response tests.

Documentation from RFC Editor explains that RFC 5782 defines a standard format for reporting email abuse, enabling ESPs to share information about spammers. This facilitates collaboration in identifying and blocking malicious senders.

Documentation from Spamhaus.org explains that Spamhaus maintains real-time blocklists (RBLs) of IP addresses and domains known for sending spam, which ESPs can use to filter out unwanted email. These lists are compiled based on evidence of spam activity and are constantly updated.