Every Gmail sending limit, in one table

Gmail has four separate sets of limits, and automations usually trip a different one than people expect. Personal @gmail.com accounts are capped at 500 messages a day and 500 recipients in a single email. Google Workspace accounts get 2,000 messages a day per user, but also a 10,000 total-recipient cap, a 3,000 external-recipient cap, and a 3,000 unique-recipient cap, with lower numbers for trial accounts and mail merge. The SMTP relay service (smtp-relay.gmail.com) has its own per-user and organization-wide ceilings for devices and apps that send on behalf of a Workspace domain. The Gmail API layers quota units on top: 6,000 units per user per minute, where a single messages.send costs 100 units.

The important detail is that the daily sending limits are per user and shared across every client. Google's API error guide says the limits are "shared by all of the user's clients, whether API clients, built-in or web clients, or SMTP MSA." A script, a Zap and you typing in the web UI all draw from one budget, measured over a rolling 24 hours rather than resetting at midnight.

Every value below comes from Google's help center or developer documentation, verified November 12, 2026. Google states it may change these limits without notice. For limits on mail sent from Apps Script (MailApp/GmailApp), see Apps Script quotas.

Google's consumer help page states the caps as thresholds that trigger an error: more than 500 emails sent in a day, or more than 500 recipients in a single email. The page also documents a separate block when many of your messages bounce, and a recipient-side message that is not about your limit at all. Attachment size is a per-message cap, not a daily quota. When a file is too large, Gmail switches to a Google Drive link instead of attaching it.

Workspace limits are per user account and apply over a rolling 24-hour window. Several caps run in parallel: messages, total recipients, external recipients and unique recipients. Whichever you reach first stops sending. Mail merge sends have their own lower ceilings, and trial accounts are restricted further until the subscription is paid. After any limit is hit, the user can't send new mail for up to 24 hours. They can still receive mail and use other Google services.

The Workspace SMTP relay service is meant for devices and applications (printers, CRMs, on-premises servers) that send mail through your domain. It has higher ceilings than a mailbox, but they are still fixed. Per-user limits key off the envelope sender (MAIL FROM), not the From or Reply-To header. Envelope senders that aren't registered users aren't subject to per-user limits, though they still count toward the organization total. Trial accounts and accounts with an unpaid bill get lower limits.

The Gmail API meters work in quota units, not requests. Each method has a cost, and the per-user budget is 6,000 units per minute per project. Because messages.send costs 100 units, one user can call it at most 60 times a minute before the API's per-minute quota stops them. The daily sending caps above still apply on top. Per-minute project and per-user quotas can be raised through the Google Cloud console, but per-user mail sending limits cannot.

In the Gmail web interface, a personal account sees You have reached a limit for sending mail. Workspace users may see You have reached a limit for sending email., You reached a Gmail sending limit. or You exceeded the maximum recipients. Sending is blocked for up to 24 hours (Google says 1 to 24 hours for personal accounts). Receiving mail and other Google services keep working.

Through the Gmail API, a daily sending cap returns HTTP 429 Too many requests: User-rate limit exceeded (Mail sending) with a retry time. Google warns that this "might result in these errors for multiple hours," and that there can be a delay of several minutes before the 429s begin, so a 200 response does not prove the email was sent. Per-minute quota overruns return 403 userRateLimitExceeded or 429 rateLimitExceeded and clear within a minute. The SMTP relay service returns an SMTP error code. Workspace admins can look up the exact code in the SMTP relay error messages article.

Send to a group, not a list. Google's own advice for the 500-recipient error is to create a Google Group and address the message to the group.

Spread the volume. Limits use a rolling 24-hour window, so pacing a large send across the day avoids the cliff. For API work, use exponential backoff on 429s and batch calls (messages.batchModify costs 50 units versus many individual calls).

Use the right product. Workspace raises the mailbox cap from 500 to 2,000 a day. Apps and devices sending on behalf of a Workspace domain belong on the SMTP relay service. Newsletters and transactional mail at scale belong on a dedicated email service provider, since Gmail mailboxes are built for person-to-person mail.

Request quota increases for per-minute API quotas in the Google Cloud console. Per-user sending limits can't be increased.