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Aastha Shaw / August 4, 2023 March 12, 2025

14 Types of Email Address Hurting Your Email Deliverability


14 Types of Email Address Hurting Your Email Deliverability

When it comes to email deliverability, the types of email addresses in your mailing list play a critical role. However, it's essential to recognize that not all email addresses are created equal. While some email address types clearly pose risks to email deliverability, others may not be inherently 'bad' but can still impact your email marketing efforts.

There are plenty of other scenarios where an email address is valid but it still would not receive your email or the recipient might never open the email, resulting in a negative impact on your deliverability score.

Upon verifying millions of email lists thoroughly and studying the campaign performances, we at Clearout, have identified the different types of email addresses that can significantly impact your email deliverability.

Understanding these email address types will help you to make informed decisions about list management, segmentation, and engagement strategies, ultimately improving the overall effectiveness of your email campaigns. Let’s dive in!

Table of content:


14 Email Address Types Hurting Your Email Deliverability
● High Risk or Bad Email Address
1. Disposable Emails
2. Spam Traps
3. Invalids & Typos
4. Duplicates
5. Blacklisted Email Addresses
6. Purchased Emails
7. Human-Generated Gibberish Emails
8. Spam Bots
● Engagement Based Email Address
9. Inactive/Abandoned Email Accounts
10. Unsubscribes
11. Bounced Emails
● Less Risky or Conversion Potential Email Address
12. Catch-all Emails
13. Free Emails
14. Role-Based Emails
● How To Avoid Bad Email Addresses?
● Remove Bad Email Addresses & Segment Smartly For Better Email Deliverability

14 Email Address Types Hurting Your Email Deliverability


We have listed 14 types of email addresses that can be highly responsible to keep you from meeting your email deliverability and engagement goals.

High Risk or Bad Email Address


Identifying and understanding high-risk email address types is crucial for maintaining a healthy email list and ensuring optimal deliverability. Let's explore the email addresses that pose potential risks to your email campaigns.

1. Disposable Emails


A disposable email or a temporary email address is the type of email that self-expires after a certain period (mostly a few days or a few minutes). These types of emails are used by individuals who want to avoid receiving emails from your business or signing up for your services without revealing their primary email.

Lead Magnets that are promoted aggressively online would see a high number of disposable email addresses.

Here is an example of a temporary email address created from temp-mail: "[email protected]"

Since these addresses are short-lived, sending emails to them is futile and can harm your deliverability.

2. Spam Traps


Spam traps are email addresses created with the sole purpose of identifying spammers. These addresses are not actively used by individuals but are created and maintained by email service providers, internet service providers, and anti-spam organizations.

Spam Traps identify senders who are not obtaining consent before sending emails. So if you have somehow got a spam trap in your email list, you can end up in a big mess, even to the extent of getting blacklisted.

3. Invalids & Typos


Invalid emails are emails that are not in the correct format or do not match any existing email account, i.e., they don’t exist. When people sign up for your service, they might make typos. People might also try to enter your system with fake/invalid email addresses.

Such email addresses clog up your email list with incorrect and bad data. Not only do these invalid addresses bounce back your emails, damaging your sender's reputation, but they also waste your valuable resources. To avoid the invalids & typos, implement a proper email validation method that only allows valid email addresses.

4. Duplicates


Sometimes, an email address can end up more than once in your email list. This can be when the user submits their email multiple times through different sources (contests, for freebies, etc), or may be due to poor list management.

Imagine sending out the same email to the same person more than once, it can get annoying when this error keeps happening. The recipient would consider this as spamming and will soon mark you as spam which can lead to poor email deliverability.

5. Blacklisted Email Addresses


Blacklisted emails are email accounts that are suspected of malicious or spam activities and hence are these blocked by the email blacklists. When you send emails to a blacklisted email address, there are a few possible outcomes.

Firstly, the email may be rejected by the recipient's email server and not delivered. In this case, you may receive a bounce-back message indicating that the email was not delivered due to being blacklisted.

Secondly, if the email does get delivered to the recipient's inbox, it may be automatically flagged as spam. This means that the email could end up in the recipient's spam or junk folder instead of their primary inbox. As a result, the chances of the recipient seeing and opening the email are significantly reduced.

6. Purchased Emails


Purchased email addresses typically come from third-party sources such as data brokers that specialize in collecting and selling email addresses, without the consent of the email owners.

These email addresses are often outdated, with many inactive or non-relevant email addresses. As a result, your emails fail to reach potential customers and are lost in a void of non-existent inboxes, damaging your sender's reputation along the way.

7. Human-Generated Gibberish Emails


Gibberish email addresses are email addresses that are randomly generated by individuals and do not make any logical sense.

It can have a detrimental impact on your email deliverability as you send emails to nonsensical addresses, i.e., to non-existent recipients. This indicates that your email list may contain irrelevant or potentially harmful email addresses and can trigger red flags for ESPs.

As a result, sending emails to this email address type not only wastes your resources but also negatively impacts your sender's reputation.

Example of what a gibberish email address may look like: "[email protected]" or "[email protected]"

8. Spam Bots


Spam bot activities and fake spam form submissions are very common today. Spam bots are automated programs designed to generate fake email addresses and fill your forms on a massive scale.

These malicious bots infiltrate email lists, often undetected, and lead to a high number of bounce-backs, ultimately hurting your email deliverability.

Clean Now

Engagement Based Email Address


Why do we send email campaigns? To engage with our audience right?

But even when your emails reach your recipient’s inbox, and they don’t engage with your emails, it is going to harm your email deliverability.

In this section, we’ll delve into email address types that reflect the level of engagement with your campaigns and how they can impact your deliverability.

9. Inactive/Abandoned Email Accounts


Inactive or abandoned email accounts are the ones that are no longer being used by their owners. It can be an email account that belonged to an employee, and when they switch their company, their previous email address is abandoned.

If you keep sending out emails to these accounts you will never get any engagement and it will only contribute to a low email deliverability score.

10. Unsubscribes


There will always be people who (intentionally or unintentionally) opted to receive your emails, but later on, might not want to receive them anymore due to changed preferences, and want to opt-out.

In this case, respecting their decision and removing their email address from the list is important. Not doing so and still sending out emails to unsubscribed accounts can be considered spam activity, and lead to legal consequences, tarnished sender’s reputation, and poor email deliverability.

11. Bounced Emails


Bounced email addresses refer to email addresses that are undeliverable or unable to receive messages. There are two types of bounces — "Hard bounces" when the email address is deleted, permanently invalid, or non-existent, and "Soft bounces" occur when the email is temporarily undeliverable, often due to a full inbox, busy server, etc.

When an email is sent to a bouncing address, it "bounces back" to the sender, usually accompanied by a notification or error message indicating the reason for the bounce.

bounced email addresses causing poor email deliverability

Soft bounces are temporary issues and might not cause much harm to your email deliverability, but hard bounces are to be immediately dealt with to avoid a high bounce rate and poor email deliverability.

Less Risky or Conversion Potential Email Address


Conversions are the lifeblood of email marketing success. Learn about different email address types that may affect your conversion rates and why you need to optimize your strategies accordingly.

12. Catch-all Emails


Catch-all email addresses are like a big net that catches any email sent to a domain, whether or not the address exists. But, they can still mess up email deliverability in a few ways.

Since catch-all addresses accept emails from even non-existing addresses, they tend to get flooded with spam messages. If someone sends an email to a wrong or misspelled address, the catch-all address will accept it but then bounce it back later if unengaged. This can make it harder for your emails to reach people's inboxes.

Moreover, bounce handling relies on accurate bounce codes. But with catch-all addresses, since all emails are accepted, it can mess up the bounce handling system.

13. Free Emails


Free emails are email addresses provided by free email service providers like Gmail, Yahoo Mail, or Outlook.com. Email campaign performance largely depends on what your goals are, who your target audience is, and how well you segment your list.

While free emails are not much risky, if you are in a b2b, you might want to avoid including personal and free email addresses in your campaign, to avoid being irrelevant and maintain good email deliverability. Whereas if you are in b2c, free emails will be forming the majority of your subscriber base.

14. Role-Based Emails


Role-based email addresses are generic email addresses associated with a particular role or function
rather than an individual person.

For example, "[email protected]," "[email protected]," or "[email protected]."

These addresses are often accessed by multiple people or teams responsible for handling specific tasks or inquiries. Emails sent to role-based addresses often lack personalization, which can result in lower open rates, email engagement, and email deliverability.

While you can’t avoid sending emails to all types of emails for your campaigns, you can definitely take some measures to avoid the bad and unwanted ones. Here’s how…

How To Avoid Bad Email Addresses?


✅ Double opt-in - It is a two-step verification method where the user is added to your email list only after they confirm opting in twice. This ensures that they are willingly opting in for your emails and will mostly be engaging with your emails, helping you maintain a high email deliverability score.

✅ ReCaptcha - It is an effective way to reduce the spam bot activities on your forms. The user is required to check a captcha box or solve a puzzle or enter text to prove they are human. This method combined with other email verification can greatly reduce bad email addresses and spam submissions on your forms.

 ReCaptcha to remove spam and bad email address types

✅ Build email list organically - Rather than purchasing email lists, focus on building a high-quality email list with your target audience organically. It might take some time, but such email addresses will be more relevant to your business goals, and also more likely to engage with your emails.

✅ Setting up real-time email verification - Real-time email verification services help you validate and stop bad email addresses as they are being entered into the system.

Clearout’s real-time email verification stops bad email addresses (especially spam bots, disposables and spam traps) at the point of capture so they don’t pass through your contact forms or signups.

✅ Regular email list validation - If unwanted and risky email addresses have already been entered into your system, you can bulk verify your email lists and keep them clean.

Clearout helps you identify spammy, risky, invalid, and duplicate email addresses through their bulk cleaning option.

Clearout also classifies email addresses into guaranteed deliverables, which minimizes your bounce rate to less than 3% and ensures a high deliverability score.

Remove Bad Email Addresses & Segment Smartly For Better Email Deliverability


As we put in efforts for removing bad email address types, effective segmentation, and regular email list cleaning are also important to remove unwanted emails from your email campaigns.

You should segment your email list based on your email marketing goals. Say, if you are a b2b business, you should segment your list based on decision-makers, pain points, etc, while avoiding role-based and free email accounts.

Also, check your email lists for catch-alls and engagement-based email address types, and proactively deal with them. To do so, every month or quarter, review your engagement metrics and take necessary action to maintain properly segmented & high-quality email list types that lead to better email deliverability.
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