What are the best lists of temporary email account generators and should they be blocked?

Summary

The answers present a diverse perspective on managing temporary email addresses. Some sources advocate for blocking them to prevent abuse, spam, and maintain data quality, citing their use in malicious activities like creating fake accounts and distorting marketing metrics. They recommend leveraging regularly updated blocklists, server-side validation, and email verification services. However, other sources caution against outright blocking, highlighting that legitimate users utilize temporary emails for privacy reasons. They propose alternative strategies like flagging disposable emails, implementing stricter verification methods, and focusing on preventing the negative outcomes associated with temporary emails (e.g., fake accounts) rather than targeting the addresses themselves. It's also noted that blocking major email providers to prevent temporary addresses can harm sender reputation. Maintaining these blocklists is an ongoing effort, and a contextual approach that balances data quality with user experience is crucial.

Key findings

  • Disposable Lists: Lists of disposable email domains and IPs are available (e.g., GitHub repositories, StopForumSpam).
  • Blocking Benefits: Blocking disposable emails can prevent abuse, spam, and improve data quality by reducing fake sign-ups and improving the quality of the user base.
  • Ongoing Effort: Maintaining a blocklist of disposable emails requires constant updates to remain effective.
  • Privacy Concerns: Disposable emails can be used for legitimate privacy reasons, so blocking them may affect certain users.
  • Alternative Approach: An alternative approach is to flag disposable emails and apply stricter verification measures (e.g., phone verification).
  • Negative Impact: Disposable emails can negatively impact email marketing efforts, sender reputation, and marketing metrics.
  • Focus on Outcomes: Preventing temporary email addresses is difficult, so focusing on the outcomes you're hoping to prevent (like fake accounts) can be more effective.
  • Verification Methods: Email verification services and checking domain reputation can help detect disposable email addresses.

Key considerations

  • False Positives: Consider the potential for false positives when blocking disposable emails.
  • List Maintenance: Be prepared to continuously update and maintain any blocklist used.
  • Strategic Approach: Develop a comprehensive strategy that balances data quality, user experience, and security when addressing disposable emails.
  • Reputation Impact: Consider the potential impact on sender reputation if blocking major email providers.
  • Alternative Solutions: Explore alternative verification and fraud detection methods to minimize reliance on blocking disposable emails.
  • Contextual Approach: The decision to block or allow disposable emails should be based on the specific context and goals of your service.

What email marketers say
9Marketer opinions

The responses indicate a multifaceted approach to handling temporary email addresses. While several sources advocate for blocking disposable emails to prevent abuse, spam, and maintain data quality, others suggest a more nuanced strategy. This involves flagging disposable emails and implementing stricter verification methods (e.g., phone verification) instead of outright blocking. The potential negative impact on legitimate users who value privacy should also be considered. Email verification services and regularly updated blocklists are frequently recommended.

Key opinions

  • Blocking Benefits: Blocking disposable email addresses can prevent abuse, spam, and improve data quality.
  • Ongoing Maintenance: Maintaining a blocklist requires continuous updates to stay current with new disposable email services.
  • Alternative Approach: Flagging and applying stricter rules to disposable emails can be a viable alternative to outright blocking.
  • Negative Impact: Disposable email addresses can negatively impact email marketing metrics and sender reputation.
  • Email verification: Email verification services can help identify disposable addresses.

Key considerations

  • Legitimate Users: Blocking disposable emails may affect legitimate users who use them for privacy reasons.
  • Verification Methods: Consider implementing alternative verification methods (e.g., phone verification) for flagged disposable emails.
  • Data Quality vs. User Experience: Weigh the benefits of improved data quality against the potential negative impact on user experience when blocking or flagging disposable emails.
  • Outcome Focus: Consider focusing on the outcome you're hoping to prevent (like fake accounts) by implementing measures to identify and deal with the outcome.
Marketer view

Email marketer from Email Hippo explains that blocking disposable emails can improve data quality and prevent fake sign-ups. However, they also note that some legitimate users might use temporary emails for privacy reasons, so consider the potential impact on user experience.

October 2024 - Email Hippo
Marketer view

Email marketer from ZeroBounce shares that disposable email addresses are often used for malicious purposes, such as spamming and creating fake accounts. They recommend using an email validation service to detect and block these addresses.

May 2024 - ZeroBounce
Marketer view

Email marketer from Reddit suggests that instead of hard blocking disposable email addresses, consider flagging them and applying stricter rules. For example, require phone verification or limit access to certain features. This allows you to still capture some users while mitigating potential abuse.

December 2022 - Reddit
Marketer view

Email marketer from Reddit shares that maintaining a blocklist of disposable email addresses is an ongoing effort. They suggest using community-maintained lists and regularly updating your own to keep up with new disposable email services.

February 2024 - Reddit
Marketer view

Email marketer from Mailjet shares that disposable email addresses can negatively impact email marketing efforts. They can lead to lower engagement rates, higher bounce rates, and damage sender reputation. Mailjet advises using email verification to filter out disposable addresses.

April 2023 - Mailjet
Marketer view

Marketer from Email Geeks shares a link to a list of disposable email domains: <https://github.com/martenson/disposable-email-domains/blob/master/disposable_email_blocklist.conf>

February 2022 - Email Geeks
Marketer view

Email marketer from Stack Overflow explains the benefits of blocking disposable email addresses. They state that it helps prevent abuse, spam, and protects against users who only want to use a service once. It can also improve the quality of your user base by ensuring users provide legitimate contact information.

February 2022 - Stack Overflow
Marketer view

Email marketer from Kickbox recommends email verification tools like Kickbox to identify disposable emails. It helps improve deliverability and prevents spam traps.

November 2021 - Kickbox
Marketer view

Email marketer from NeverBounce shares that disposable email addresses are often used to sign up for free trials, access gated content, or create multiple accounts. He shares this can distort marketing metrics and indicates potentially fraudulent activity.

June 2024 - NeverBounce

What the experts say
3Expert opinions

The provided answers suggest a cautious approach to blocking temporary email addresses. One source provides a list of disposable email domains, but others highlight the potential ineffectiveness and harm of blocking them. They note that users can easily create throwaway accounts on major platforms like Yahoo or Gmail, and blocking may damage sender reputation without solving the underlying problem. A key recommendation is to focus on preventing the harmful outcomes associated with temporary emails, such as fake accounts, rather than trying to identify and block the addresses themselves.

Key opinions

  • Disposable Lists Exist: Lists of disposable email domains are available.
  • Blocking Ineffective: Blocking known disposable email addresses can be easily circumvented and may not be effective.
  • Reputation Damage: Blocking major email platforms can harm sender reputation.
  • Outcome Focus: Focusing on the harmful outcomes (e.g., fake accounts) is more effective than blocking temporary emails.

Key considerations

  • Strategic Approach: Develop a strategic approach that addresses the underlying problems associated with temporary emails rather than relying solely on blocking.
  • Reputation Impact: Consider the potential impact on sender reputation before implementing aggressive blocking policies.
  • Alternative Solutions: Explore alternative solutions, such as improved account verification and fraud detection mechanisms.
Expert view

Expert from Email Geeks explains that blocking known disposable email addresses can be ineffective and potentially harmful. He shares that people can easily create throwaway addresses on major platforms like Yahoo or Gmail. Blocking disposable emails can damage your reputation at those platforms as they will not bounce but also won't interact with your mail.

November 2023 - Email Geeks
Expert view

Expert from Word to the Wise responds that preventing temporary email addresses is difficult and likely not worth the effort. Instead, focus on the outcome you're hoping to prevent (like fake accounts). Implement measures to identify and deal with the outcome, instead of trying to identify temporary email addresses.

April 2023 - Word to the Wise
Expert view

Expert from Email Geeks shares a link to a list of disposable email domains: <https://github.com/ivolo/disposable-email-domains>

October 2024 - Email Geeks

What the documentation says
6Technical articles

The provided documentation offers various perspectives on disposable email addresses. OWASP and StopForumSpam suggest using regularly updated lists and server-side validation to block disposable emails and prevent spam/abuse. Hunter.io suggests methods like checking domain reputation and using email verification tools. Conversely, Mailfence highlights the legitimate privacy reasons for using disposable emails. Wikipedia provides a general definition. While RFC 2606 doesn't list disposable emails, it underscores the importance of domain standardization.

Key findings

  • Blocklist Resources: Regularly updated lists of disposable email domains and IPs are available (StopForumSpam).
  • Server-Side Validation: Server-side validation can prevent the use of disposable emails during account creation (OWASP).
  • Privacy Use: Disposable emails can be used for legitimate privacy reasons (Mailfence).
  • Detection Methods: Domain reputation and email verification tools can aid in detecting disposable emails (Hunter.io).
  • Domain Standardization: Domain standardization is important, though not directly related to disposable emails (RFC 2606).

Key considerations

  • False Positives: Blocking all disposable emails may lead to false positives and impact legitimate users.
  • List Maintenance: Maintaining an updated list of disposable email domains requires ongoing effort.
  • Contextual Approach: The decision to block disposable emails should consider the specific context and potential impact on user experience.
  • Alternative Verification: If disposable emails are blocked, provide alternative verification methods.
Technical article

Documentation from OWASP (Open Web Application Security Project) recommends implementing server-side validation to prevent the use of disposable email addresses during account creation. They suggest using a regularly updated list of known disposable email domains or a real-time API to identify and block these addresses.

September 2022 - OWASP
Technical article

Documentation from Wikipedia defines disposable email addresses as a service that allows users to receive emails at a temporary address that expires after a certain time. This allows users to avoid giving out their primary email address to untrusted websites.

April 2021 - Wikipedia
Technical article

Documentation from Hunter.io explains methods for detecting disposable email addresses. It suggests checking the domain's reputation, looking for common disposable email patterns, and using email verification tools.

April 2023 - Hunter.io
Technical article

Documentation from StopForumSpam offers a regularly updated list of disposable email domains and IPs. This resource can be used to prevent spammers from creating accounts on forums and other online platforms using temporary email addresses.

February 2022 - StopForumSpam
Technical article

Documentation from Mailfence support explains that disposable email addresses can be used for privacy reasons to avoid spam and protect personal information. Some users may prefer to use them when signing up for services they don't fully trust.

August 2022 - Mailfence
Technical article

Documentation from RFC 2606 defines reserved domain names for documentation purposes. While not a list of disposable email domains, it highlights the importance of standardizing domain usage and identifying domains for specific purposes.

February 2024 - RFC Editor