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Imagine working hard on an important email and then discovering that the address you used is not valid when you send it.
It’s even worse if it happens with your email marketing.
You just can’t let tens or even hundreds of your clients miss your emails!

How can you tell if an email address isn’t working and make sure your campaigns reach the right people?
Read on to learn how to spot a bad email address on your list!

What is an Invalid Email Address?

An invalid email address is one that can’t receive emails, possibly because of:

• Typos or mistakes in the formatting
• Deleted or inactive domains/accounts

Some emails also only last a short time — these are disposable or temporary addresses.

Are Invalid Emails Bad for Your Lists?

Yes.
Emails that don’t work are useless on your list.

👉 If you keep invalid emails, you’ll keep paying your ESP but never reach those addresses.

They also send back hard bounces, which can:

• Hurt deliverability
• Damage your sender reputation
• Even get your IP address blacklisted if hard bounces exceed 2%

How Common Are Invalid Emails?

According to turboSMTP data (500,000+ email addresses from online forms):

• 22% are invalid
• 15% have typos
• 7% are abandoned/inactive

👉 This means over 50% of emails on your list could be useless and dangerous for delivery!

Reasons Why Emails Don’t Work

1. Typos or Wrong Format

Valid format: name@domain.com
Rules:

• No spaces
• Only one @ sign
• No double dots or illegal characters

Common mistakes include:

• #@%^%#$@#$@#.com
• @domain.com
• name@domain@domain.com
• name..name@domain.com
• name@-domain.com

👉 Correct format example: firstname.lastname@domain.com

2. Domain Taken Down

• If a company shuts down or changes providers, their domain email addresses stop working.
• When employees leave, their accounts are often deleted.
• Some providers (like Microsoft) allow temporary recovery, but deleted mailboxes are still inactive.

3. Email Changed or Discarded

• Users may switch usernames or domains, abandoning old inboxes.
• Inactive accounts get deleted after a certain time:
  • Gmail → deleted after 2 years of inactivity
  • Outlook/Hotmail/Yahoo → inactive after 1 year+

4. Disposable/Temporary Emails

• Disposable/burner emails are used to avoid spam.
• They last 10 minutes, 1 hour, or max 2 days.
  👉 These addresses inflate sign-ups but lower long-term engagement.

ALSO READ: Email Marketing for Agencies: Top Tools, SOPs, and Insights to Cut Inbox Chaos

How to Fix Invalid Emails

1. Double-Check Spelling

• Verify manually entered addresses.
• Look for:
  • Misspellings
  • Extra dots
  • Wrong domains

2. Use an Email Verifier

• Verifiers confirm whether an email is real and active.
• They may check mail servers or send an activation link.
  👉 Verification protects your reputation, improves deliverability, and reduces hard bounces.

3. Collect Other Contact Info

• Don’t rely only on email.
• Collect phone numbers, social media handles.
• Helps with:
  • Omnichannel marketing
  • Re-engaging users who changed emails

4. Never Buy Email Lists

• Purchased lists often contain:
  • Invalid emails
  • Disposable addresses
  • Contacts who never opted in

👉 This breaks laws like CAN-SPAM, GDPR, and CCPA.
👉 Fines: up to $53,088 per email (CAN-SPAM).

Always collect emails yourself with:

• Pop-up/embedded forms
• Double opt-in

Final Thoughts

There are several reasons why subscribers might not get your email — most often typos, deleted accounts, or temporary addresses.

👉 Don’t waste money on invalid emails. Clean your list regularly.
👉 Before sending campaigns, remove invalid addresses.

When you’re ready, use Selzy to create and send your emails!