Mixmax sends your messages through your Gmail account, so they are subject to any limitations set by Google, including message-sending rate limits. Google monitors the rate at which messages are sent through your account, not just the total number of messages you send in a 24-hour period. To learn more, see Google's specific account limits. This means your account could be limited if you send a high volume of messages in a short period.

Mixmax has safeguards in place to help prevent rate limiting. If you send your Sequence to more than 500 recipients at once, we will space out your sending over multiple days — 500 messages per day — and space out the send times throughout the day. Review some best practices for setting up Sequences. Mixmax may limit the number of emails a single user can send in a day to 1000 to prevent Google from rate-limiting users (we use Gmail as the underlying email service). To learn more, see Gmail's specific account limits.

Even with these precautions, your account can still get rate-limited. If it does, Mixmax may be unable to send some of your Sequence messages. The affected recipients are marked as failed in the Sequence, and you can retry the undelivered messages once the limit is lifted.

After your account is rate-limited, we recommend waiting 24 hours before retrying unsent messages to avoid triggering another rate limit. To retry sending messages, go to the Recipients tab for the affected Sequence and click the Recreate button — see the screenshot below:

The system will try to resend your emails, spacing the send times to minimize the chance of being rate-limited again.