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 of time.
Mixmax has some safeguards in place to help prevent your account from getting rate-limited. 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. Take a look at 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 in place, there is still the possibility that the account will get rate-limited. If your account is rate-limited, we may be unable to send all of your sequence messages. If this happens, we will notify you via email so you won't be left wondering. If you receive this email, you can re-try the undelivered messages.
How to retry sending undelivered messages
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. The email you received includes a link to the sequence. 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.