non existent gmail address?

[Frog]

What's up with this?
I keep getting emails from an gmail email address, that when I reply, the replies keep getting kicked back with a Delivery Failure message saying
(after RCPT TO): 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  https://support.google.com/mail/?p=NoSuchUser l124-v6si4068158itd.16 - gsmtp

Since these are replies, I am not mis-typing the address

[ebscreen]

They have their "reply-to" address set incorrectly. Look at the headers for the actual "from" address.

[Frog]

But I also copied and pasted their "from addresss" and tried another from my yahoo mail. shouldn't that have worked?

[ebscreen]

Not if they have their reply-to misspelled. You have to dig through the headers to find out.

Also, many times, the mistake can be obvious.

[blue moon]

Or it could be spam. . .

Pierre