550 5.1.1 — The email account that you tried to reach does not exist (Gmail)
Retrying will not help. The message will not be delivered.
The reply
550 5.1.1 The email account that you tried to reach does not exist.There is no mailbox at that address. Nothing is wrong with your server, your DNS or your message — the address is wrong, and no amount of retrying will create it. This is the most common permanent failure there is, and what it is really telling you is where your addresses come from.
What it means
Gmail accepted the connection, read the recipient and found nothing behind it. A 5.1.1 is final: the address was mistyped, the account was deleted, or it never existed. The individual bounce is harmless; the rate is not. Every receiver counts how often you send to addresses that do not exist, because a sender who does not know who their recipients are looks like a sender who did not collect them.
Why it happens
- A typo at signup — gmial.com, gmai.com, a missing letter in the local part. These are the bulk of it.
- The account was closed or deleted. Google does not recycle Gmail addresses, so the failure is permanent.
- The address was guessed, bought or scraped rather than confirmed.
- A Workspace user who left and whose account was removed without a forwarding rule.
- An alias or group that used to exist and was deleted.
What to do
- Remove the address from your list now and never send to it again. Suppression is the entire fix.
- Never retry a 5.1.1. It is permanent by definition and a retry is a second rejection against your reputation.
- Add confirmed opt-in so an address proves itself before it enters the list. It is the only durable fix for the underlying problem.
- Validate the syntax and the domain at the point of entry, and catch the common misspellings of the big providers — a typo check on the domain removes most of these before they are ever sent.
- Watch the rate, not the individual bounce. Persistently above a few percent means your collection is broken, and every receiver is scoring you on it.
Questions
Could the address exist but be blocking me?
No. Gmail answers a blocked sender with a 5.7.x policy code, not 5.1.1. This reply means there is nothing at the address at all.
It worked last month.
Then the account has since been closed or deleted. Gmail addresses are not recycled, so it will not come back — suppress it.
What bounce rate is too high?
Google publishes no single figure, but anything persistently above a few percent is worth acting on. Ours triggers an automatic review of the sending domain at 30%, which is a backstop rather than a target.