Does 550 5.4.5 mean my account is banned or my password is wrong?

No. This is the one thing people panic about that isn't happening. 550 5.4.5 is a volume ceiling — you sent more mail in the last 24 hours than Google lets that account send, and it stopped accepting new outbound messages until the window clears. You can still receive mail, read your inbox, and use every other part of the account normally. A wrong password gives you a 535 authentication error, and a disabled account gives you 5.2.1 or a suspension notice — different codes, different problems. If you're seeing 5.4.5, the account is fine; you just talked too much.

How long until 550 5.4.5 clears? Can I reset it manually?

You can't reset it, and neither can a Google Workspace admin — the cap is a rolling 24-hour window, not a counter that zeroes at midnight. That distinction matters: if you burned through your quota in a burst at 2pm, you don't get it all back at midnight, you get it back gradually as those individual sends age past the 24-hour mark. In practice most accounts are sending again within a few hours to a day. There is no 'unlock' button, no support ticket that speeds it up. Waiting is the only lever, and if you're waiting often, the quota isn't the real problem — how you're sending is.

Why did I hit the limit after only a handful of emails?

Because Gmail counts recipients, not messages — and it counts every address in To, Cc, and Bcc, plus every failed and bounced recipient. Five emails to a 200-person distribution list is a thousand recipients, not five. Mailing a stale list where half the addresses are dead still burns quota on the dead ones, because a delivery attempt was made. And if the number genuinely makes no sense — you sent three personal emails and hit the wall — suspect the account is compromised and quietly blasting spam in the background. A sudden 5.4.5 with low personal volume is a classic account-takeover tell; change the password and check the Sent folder before anything else.

What are the actual daily limits?

For a free Gmail account, roughly 500 recipients per rolling 24 hours through the web, and historically tighter through an SMTP client. For a paid Google Workspace account, 2,000 messages per day per user, with a cap of 3,000 unique recipients (2,000 of them external). Google's own relay service, smtp-relay.gmail.com, allows up to 10,000 recipients a day and is the sanctioned path for bulk or app-generated mail. But treat every number as a ceiling, not a promise: Google also applies behavior-based throttling underneath the published caps, so a suspicious pattern can trip 5.4.5 well before you reach the stated limit.

550 5.4.5 Daily User Sending Quota Exceeded

Problem

A message bounces, or your mail client throws an error, containing 550 5.4.5 Daily user sending quota exceeded followed by a server ID like gsmtp. Outbound mail stops. Your inbox still works fine — you can read, receive, and open everything — but nothing you send goes out.

What 550 5.4.5 Actually Means

Strip the jargon and it says one thing: you have sent too much in the last day, so I’ve stopped accepting more from you for now.

The 550 is a permanent rejection (a 5xx code), but “permanent” here means “permanent for this attempt” — it is not a permanent ban. The 5.4.5 is the enhanced status code, and the .4. class is about network and routing conditions, not authentication or bad addresses. Google’s plain-text gloss on it is “Daily user sending quota exceeded.” That’s the whole story. This is a rate limit wearing the costume of a hard failure.

Which means the two things people immediately assume are both wrong. It is not an authentication problem — a bad password gives you 535. It is not a suspended account — that gives you 5.2.1 or a suspension page. Your credentials are valid, your account is alive, and the only thing broken is that you’ve used up a budget.

The Fork That Decides What You Do Next

Before you touch anything, answer one question: does the number of recipients you sent actually justify hitting the limit?

Gmail counts recipients, not messages, and it counts everyone in To, Cc, and Bcc — plus every address that bounced, because a delivery was attempted. So the honest accounting is often much higher than “I sent a few emails.” Five newsletters to a 300-person list is 1,500 recipients. A script retrying failed sends counts each retry. A mailing to a list that’s half-dead still spends quota on the dead half.

If the math adds up — you were doing real bulk sending, or hammering a big list — then you hit a legitimate ceiling, and the fix is about how you send (below).
If the math doesn’t add up — you sent a dozen personal emails and slammed into the wall — stop and assume the account is compromised. A quiet spam run from a hijacked account is the single most common reason a light personal user sees 5.4.5. Change the password, kill active sessions, and read the Sent folder before you do anything else.

That single check saves you from waiting out a quota reset while an attacker keeps refilling it.

Top 3 Causes

You’re using a personal mailbox as a bulk mail server. Gmail’s per-user sending — whether through the web or smtp.gmail.com — is built for a human writing emails, not for a marketing blast or a transactional queue. Free Gmail is around 500 recipients per rolling 24 hours; paid Workspace is 2,000 messages and up to 3,000 unique recipients (2,000 external) per user per day. Push newsletters, cold outreach, or app-generated mail through that pipe and you’ll hit 5.4.5 fast. This isn’t a limit to raise; it’s the wrong tool.
A stale or padded recipient list is inflating the count. Because failed and bounced recipients still count, a list full of dead addresses spends quota twice — once on the send, once on the reputation hit. Large distribution lists, Cc/Bcc walls, and automated retries all quietly multiply the recipient tally past what “I sent N emails” would suggest.
The account is compromised and sending spam you can’t see. When a light personal user trips a bulk-mail ceiling, the cause is usually mail you didn’t send. Attackers use hijacked accounts to send spam until the quota chokes — the 5.4.5 is the side effect, not the problem. The tell is the mismatch: high send volume, low personal activity.

Diagnose with DechoNet

Email Check — run it on your sending domain to confirm SPF, DKIM, and DMARC are actually in place and aligned. This won’t undo a quota that’s already spent, but if you’re sending real volume, weak authentication is why Google is also throttling you underneath the published cap — and fixing it is the difference between reliable delivery and a permanent spot in the spam folder.
Reverse DNS Check — if you’re moving mail through your own server or relay rather than Gmail’s web client, a missing or mismatched PTR record drags down sender reputation, which makes Google apply its behavior-based throttling sooner. Confirm forward and reverse DNS agree.
DNS Check — verify your domain’s MX and mail records resolve the way you expect, so that when you move bulk sending off the personal mailbox, it lands on the infrastructure you think it does.

Resolution Checklist

First, do the recipient math. If the volume doesn’t justify the limit, treat it as a compromise: change the password, sign out all sessions, and audit Sent and filters before anything else.
If the send was legitimate bulk mail, stop trying to raise the per-user cap — it’s fixed, and no admin can lift it. Move that traffic to the right channel instead.
For Workspace bulk or app mail, route it through smtp-relay.gmail.com (up to 10,000 recipients/day, 100 per transaction) rather than smtp.gmail.com.
For genuine marketing or transactional volume, use a dedicated sending service built for it — a personal mailbox will never be the right home for a mailing list.
Clean the list. Remove dead addresses so bounces stop spending quota and dragging your reputation down.
Run an Email Check on the sending domain and fix any SPF/DKIM/DMARC gaps before you scale sending back up.
Then wait out the rolling window. There’s no manual reset; sending capacity returns gradually as your recent sends age past 24 hours.

When to Escalate

If you’re a Google Workspace admin and users keep hitting 5.4.5 during ordinary work, the fix isn’t a support ticket — it’s re-architecting how that mail is sent (SMTP relay, or an external email service). The per-user daily caps are not adjustable.
If the pattern points to a compromised account — high volume, low human activity, unfamiliar messages in Sent — treat it as a security incident, not a quota problem: reset credentials, revoke sessions, and review account access.
Related sender-side problems worth checking when mail keeps failing: 550 5.7.25 (reverse DNS), 550 5.7.26 (unauthenticated), and the temporary 421 4.7.28 rate limit, which is the retryable 4xx cousin of this permanent 5xx cap.

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