What are temporary email account generators?

Temporary email account generators (also known as disposable or burner email services) provide email addresses that are valid for a limited time, usually minutes or hours. They are used for privacy, to avoid spam, or to bypass signup requirements without using a primary email address. Examples include Temp Mail and 10 Minute Mail.

Should I block temporary email addresses from signing up for my service?

While blocking can prevent immediate abuse from known sources, it can also deter legitimate users who prioritize privacy. More importantly, it might push malicious users to create throwaway accounts with major ISPs (like Gmail or Yahoo), which can be more harmful to your sender reputation due to unengaged, seemingly valid addresses. For more details, see our article on whether disposable emails should be blocked .

Is there a better way to manage potential abuse from temporary email accounts than just blocking them?

Relying on behavioral monitoring is generally more effective. Instead of blocking by domain, focus on user engagement post-signup. If an account shows no activity, it can be flagged as unengaged or potentially abandoned, regardless of the email provider. This helps maintain a healthier list and protects your sender reputation more accurately.

Where can I find a list of temporary email domains?

You can find lists of disposable email domains on open-source repositories like the disposable-email-domains GitHub project . However, these lists require constant updates. Commercial email validation services often provide real-time checking against comprehensive and frequently updated lists.

What are the best lists of temporary email account generators and should they be blocked? - Technical - Email deliverability - Knowledge base

Temporary email account generators, often called disposable or burner email services, allow users to create an email address that self-destructs after a short period, typically from a few minutes to a few days. These services are commonly used to bypass registration requirements, sign up for free trials without committing personal information, or avoid spam in one's primary inbox. They serve a legitimate purpose for user privacy and convenience in many online interactions.

However, for businesses and email marketers, these temporary email addresses present a significant challenge. They can lead to inflated subscriber counts, skewed engagement metrics, and a higher risk of spam complaints if used for malicious purposes. The transient nature of these emails means that any communication sent to them is unlikely to be read or acted upon, undermining marketing efforts and potentially harming sender reputation.

The question then arises: should these temporary email account generators be actively blocked? While the immediate answer might seem like a straightforward yes, the reality is far more complex. Blanket blocking can have unintended consequences, potentially preventing legitimate users from accessing your services or creating accounts.

Identifying temporary email addresses and finding lists

Identifying temporary email addresses often involves looking for specific domain names known to host such services. There are numerous open-source projects and commercial APIs that maintain regularly updated lists of these disposable email domains (sometimes referred to as blocklists or blacklists). These lists are a starting point for recognizing email addresses that are unlikely to be genuine or long-lasting.

One of the most widely referenced resources for such domains is the disposable-email-domains GitHub repository. This community-maintained list provides a comprehensive collection of domains frequently used for temporary email services. It's updated periodically, reflecting new providers and domains that emerge, which is crucial given the dynamic nature of these services.

While useful, it is important to understand that these lists are never exhaustive and require constant vigilance. New temporary email domains appear regularly, meaning that a static list can quickly become outdated. This is why many organizations opt for dynamic solutions or strategies and resources that involve real-time checks rather than relying solely on a fixed blocklist (or blacklist).

Example of a simple disposable email blocklist

example.com
mailinator.com
10minutemail.com
temp-mail.org
yopmail.com

Why blocking temporary email accounts is considered

Many businesses consider blocking temporary email addresses to protect their data and maintain the quality of their user base. The primary reasons revolve around mitigating fraud, preventing abuse, and improving email marketing efficacy. These addresses are often used for activities like creating multiple accounts for free trials, submitting fake registrations, or engaging in spamming and phishing attempts.

From a deliverability perspective, sending emails to temporary addresses can negatively impact your sender reputation. When these emails are abandoned or quickly expire, they contribute to a higher bounce rate and lower engagement, signaling to internet service providers (ISPs) that your sending practices are poor. This can lead to your legitimate emails being flagged as spam or even blocked, affecting your overall email deliverability.

Risks of temporary emails

Fraudulent activities: Used for creating fake accounts or abusing free trials.
Skewed metrics: Inflate subscriber counts but show no engagement.
Reputation damage: Low engagement and high bounce rates hurt sender reputation with GoogleYahooMicrosoft and others.
Resource drain: Wasted resources on sending emails that will never be opened.

The nuanced perspective on blocking

Despite the apparent benefits, a blanket ban on temporary email addresses can be a double-edged sword. While it might deter some bad actors, it can also alienate legitimate users who rely on these services for privacy. Many users simply want to avoid spam or protect their primary inbox from unwanted marketing messages, especially when signing up for a service they're only testing or don't fully trust yet.

Consider the scenario where a user creates a disposable email from a common provider like Temp Mail for a one-time download or to access content they're unsure about. Blocking this user outright means losing a potential lead or customer. Furthermore, if you force users to use their primary email, they might simply abandon their account or mark your emails as spam, which can be even more detrimental to your sender reputation than a temporary bounce.

A critical point highlighted by deliverability experts is that blocking recognized disposable email domains might just push malicious users to use mainstream providers like

Yahoo or

Gmail for their throwaway accounts. This scenario is arguably worse, as you'd be sending emails to seemingly legitimate addresses that are in fact abandoned, leading to low engagement rates, high spam complaints, and ultimately, a damaged domain reputation with major ISPs. It's a subtle but significant difference, as those accounts won't bounce, masking the underlying issue.

Therefore, the decision to use an email blocklist for temporary email generators should be approached with caution. It might address the symptom but not the root cause of unwanted sign-ups. Understanding the user's intent is crucial, which a simple blocklist cannot discern.

Blocking temporary emails

Pros: Reduces immediate fraud and abuse from known sources.
Potentially improves raw bounce rate by rejecting bad emails at signup.
Cons: Alienates legitimate, privacy-conscious users.
Pushes malicious actors to use Outlook or AOL addresses instead.
Static lists are often outdated.

Focusing on engagement & behavior

Pros: Allows legitimate users to sign up using temporary emails.
Identifies truly problematic users based on their actions.
Maintains a cleaner list long-term through engagement tracking.
Cons: May allow some initial abuse or spam signups.
Requires robust behavior analytics and segmentation.

Alternative strategies for managing suspicious sign-ups

Instead of outright blocking, a more sophisticated approach focuses on managing the risks associated with temporary email accounts and ensuring your email list remains healthy. This involves a combination of validation, behavioral monitoring, and strategic list segmentation.

One effective strategy is to use real-time email verification services at the point of signup. These services can not only detect disposable domains but also identify malformed addresses, spam traps, and other risky email types. This allows you to filter out truly problematic signups without broadly penalizing privacy-conscious users. For more on this, consider resources on preventing bad signups.

Beyond validation, monitor user behavior after signup. If an email address shows no engagement, such as opens or clicks, over a sustained period, it might indicate a temporary or abandoned account. You can then segment these users into a separate list or suppress them from future mailings to protect your sender reputation. This proactive approach helps prevent fake registrations and list bombing while accommodating privacy concerns.

Best practices for managing temporary emails

Real-time validation: Implement email verification at signup to catch bad addresses.
Behavioral monitoring: Track engagement and flag inactive or suspicious accounts.
Segmentation: Separate low-engagement users to protect your primary sender reputation.
Double opt-in: Ensure users confirm their subscription, validating their intent and email address.

Views from the trenches

Best practices

Implement a robust email validation service at the point of sign-up to catch temporary emails and other invalid addresses immediately.

Prioritize behavioral analysis over domain blocking, focusing on user engagement to identify truly problematic accounts rather than just their email type.

Use double opt-in for all new subscribers; this ensures genuine interest and an active, monitored email address.

Common pitfalls

Relying solely on static blacklists (or blocklists) of temporary email domains, which quickly become outdated and miss new services.

Blindly blocking all temporary email addresses, which can alienate privacy-conscious users and drive them to use main ISPs for throwaways.

Ignoring low engagement from seemingly legitimate domains, as these could be abandoned temporary accounts at major providers.

Expert tips

Focus on the 'why' behind temporary email usage rather than just the 'what.' Many users have legitimate privacy concerns.

Segment your audience based on engagement. Treat highly engaged users differently from those who rarely open emails.

Regularly clean your email lists to remove inactive subscribers, regardless of whether they used a temporary address.

Marketer view

Marketer from Email Geeks says a master list of temporary email account generators should always be referred to when blocking these domains.

2020-07-01 - Email Geeks

Expert view

Expert from Email Geeks says that if you are not blocking domains like gmail.com or yahoo.com, then you might be making a mistake.

2020-07-01 - Email Geeks

Prioritizing smart strategies over blanket blocking

The question of whether to block temporary email account generators is not as simple as it initially appears. While the immediate impulse might be to prevent potential abuse and maintain list cleanliness, a nuanced approach is often more effective and less detrimental to legitimate user engagement.

Relying solely on static blacklists of disposable domains can be a short-sighted solution that forces bad actors to adapt by using mainstream email providers for their throwaway accounts. This can lead to a more insidious problem: abandoned email addresses that don't bounce but silently harm your sender reputation due to lack of engagement.

Ultimately, fostering a healthy email ecosystem involves smart strategies that go beyond simple domain blocking. Implementing robust email validation at the point of entry and continually monitoring user engagement and behavior are more sustainable ways to ensure a high-quality, responsive email list. This approach allows you to filter out truly harmful addresses while still accommodating users who value their privacy, ensuring your messages reach engaged recipients and protect your deliverability.