What is a Catch All email address ?
What is a Catch All E-mail address or “Unknown” email? When you verify an email address to determine if it’s valid or invalid, sometimes you can’t get an accurate response, so the email is labeled this way.
Catch All Email
The largest percentages of these Unknowns are Catch All, basically this e-mail addresses servers accept all emails.
The best way to explain this is to use the analogy of you receiving a letter at your house, delivered to your mailbox. Compared to if you live in a condo development with hundreds of different people but one main Mail-room to ACCEPT all mail.
Your house has one single address that the mail can only be delivered to, your mailbox, if you don’t live their anymore, then the mailman returns to sender (bounce back).
A condo on the other hand has one basic mail room for everyone, so all mail is accepted and then gets distributed once a gets inside. At the condo, some people may have moved, don’t live their anymore etc, but the mail was ACCEPTED. This would be where email verification ends, so we are not sure.
So when you verify an email the result will be unknown, because the verifying software (the good ones anyway) will know this domain is a catchall and label it as such. So we cannot be sure if the final email destination is valid or invalid as the catchall server doesn’t go all the way to the actual final email address.
Typically though if an email is Valid or invalid we can pick those up easier than a Catchall, so in my experience, 80-85% of all Unknown emails are actually valid. So you can mail them if you wish but I personally would never say a catchall is valid or invalid, it’s simply unknown.
Catch All Email Spam Traps
One other explanation from Go Daddy is as such:
“A catch-all email account is an address that is specified to receive all messages that are addressed to an incorrect email address for a domain. For example, you have three e-mail addresses set up for coolexample.com; email@example.com, firstname.lastname@example.org, and email@example.com, you can set up firstname.lastname@example.org as a catch-all email account. Then, any email messages sent to email@example.com (or any other invalid email address), are sent to the catch-all account (firstname.lastname@example.org).”
This is also a way spam traps catch you as you never get a bounce back, soft or hard, it just gets accepted then you hit the eventual trap once inside.