Someone signs up to your newsletter with an email address. But is it real? Is it a throwaway? Will it bounce? Here is how to check — and why it matters for your deliverability.
Types of Fake Email Addresses
- Disposable/temporary emails — Created on services like Mailinator, 10MinuteMail, and TempMail. Valid for minutes or hours, then gone. Used to bypass email gates without giving a real address.
- Role-based addresses — info@, admin@, support@, sales@ — usually go to a team inbox and have low engagement rates. Often flagged by email platforms.
- Typo addresses — Gmail.com typed as Gmai.com, yahoo.co (missing the m). Real intent, wrong address.
- Completely fake addresses — Random strings at non-existent domains. Bounce immediately.
How to Check if an Email Is Disposable
Use Anonymiz Disposable Email Checker — it checks any email address against a database of thousands of known disposable email domains and returns whether the address is temporary or permanent. Free, instant, no account needed.
How Email Verification Works
Behind the scenes, email verification tools perform several checks:
- Syntax check — Is the format valid? (something@domain.tld)
- DNS check — Does the domain exist and have MX records?
- Disposable domain check — Is the domain on a list of known temporary email services?
- SMTP check — Some tools ping the mail server to verify the specific mailbox exists without sending an email.
Why This Matters for Email Marketing
- Bounce rate — High bounce rates damage your sender reputation with email providers.
- Deliverability — Sending to too many invalid addresses gets your IP flagged as spam.
- List quality — Disposable emails never engage. They inflate list size while dragging down open rates and ROI.
Check any email address instantly at Anonymiz Disposable Email Checker. Free, no signup required.
Some mail servers are configured as "catch-all," meaning they accept mail for absolutely any address at their domain regardless of whether that specific mailbox exists — this defeats SMTP verification entirely, since the server reports every address as valid even ones that were never actually created. Larger companies sometimes run catch-all setups intentionally, making address-level validation unreliable for those domains no matter how good the checking tool is.
Syntax validation (checking the format looks like an email) and deliverability validation (checking the mailbox can actually receive mail) are genuinely different checks — an address can be perfectly formatted and still be fake, or oddly formatted and still work. A tool that only validates syntax will pass obviously fake addresses like test@test.com as "valid" simply because the format is correct, which is why real deliverability checking matters more than format checking for catching fakes.
