How can an email address suddenly be non-existent?

[chris_mo]

Trying to understand how this can be. I meet someone and email them at example@gmail.com (not their real email address, obviously). We exchange emails a few times. And then when I email them the next day, I get the following bounce back email:

*** ATTENTION ***

Your e-mail is being returned to you because there was a problem with its
delivery. The reason your mail is being returned to you is listed in the
section labeled: "----- The delivery status notification errors -----".

The line beginning with "Diagnostic-Code:" describes the specific reason
your e-mail could not be delivered. The following lines contains the
RFC822 header of the original email message.

Please direct further questions regarding this message to your e-mail
administrator.

--AOL Postmaster

----- The delivery status notification errors -----


<example@gmail.com>: host gmail-smtp-in.l.google.com[173.194.68.27]
said: 550-5.1.1 The email account that you tried to reach does not exist.
Please try 550-5.1.1 double-checking the recipient's email address for
typos or 550-5.1.1 unnecessary spaces. Learn more at 550 5.1.1
http://support.google.com/mail/bin/a...py?answer=6596 a6si716851qae.148
- gsmtp (in reply to RCPT TO command)

[janusz]

1. Trivial suggestion: you did misspell the address
2. Account disappeared because:
a) subscription not renewed if this was a paid account
b) account closed due to a breach of terms of service
c) the owner decided to close it

[chris_mo]

I replied to their email, and I ensured that the email address was spelled correctly. It was a gmail account, so the paid service theory is out. Is it possible for an email address to be spoofed in some way? Just seems weird to be shut down so quickly...

[markwolk]

Maybe they used their email to send spam, and the account was since closed?

[mollypgarvan]

I think most free emails would say it's because of a breach in the terms and conditions...