A bounce is an email that couldn't be delivered, usually because your recipient's email server rejected it. A message might be rejected for several reasons, which we call hard bounces and soft bounces. You'll see bounced messages indicated in your reports and Live Feed with a red arrow.
What is a hard bounce?
A hard bounce indicates a permanent reason your email cannot be delivered, and future attempts to email this address will result in additional bounces. Sending to a non-existent email address is the most common cause of hard bounces.
What is a soft bounce?
A soft bounce indicates a valid email address reaching the recipient's server before being returned as undelivered. In many instances, a soft bounce will be retried after a period of time. If you receive a bounce notification, it will likely indicate whether delivery will be reattempted. Soft bounces can occur for many reasons, some of which include:
Your recipient's mailbox is full.
The mail server is down.
The mail server is processing a high volume of messages.
The message is too large.
How are bounces handled for Sequences?
For all hard bounces, Mixmax will automatically exit the email address from the Sequence, so you don't have to worry about future attempted deliveries. The Insights tab in the Sequence shows the percentage and total number of emails that bounced in your current Sequence, as well as the percentage and total number of emails that bounced for each Sequence stage under Email Performance.
For soft bounces, Mixmax will continue delivering future stages, and recipients will not be exited from the Sequence.
Only the primary recipient's address determines whether someone exits a Sequence. If the primary recipient is exited, any CC'd contacts on that thread will also stop receiving the Sequence, since later stages are sent to the primary recipient.
If a CC'd or BCC'd address bounces, the primary recipient stays active and continues through the remaining stages — and the bounce is not counted in your Sequence Insights or Bounce %.
Only hard bounces for the primary recipient will appear in your Live Feed and reports.
FAQ
Why did my email bounce with a message about my Gmail sending limit?
Mixmax sends your emails through your own Google account, so Google's sending limits apply to them. When your account reaches its limit, Google rejects new emails before they're delivered. Mixmax marks these emails as bounced and sends you a bounce notification explaining that your Google account reached its sending limit. You may also get a notification from Google saying you've reached a sending limit.
This kind of bounce isn't caused by your recipient's address, so you don't need to remove or change the recipient. Google's limits apply to everything sent from your Google account, not only to emails sent with Mixmax.
The limit is usually lifted within 24 hours. Once it's lifted, send the bounced emails again. If Sequence emails weren't sent because of the limit, see How to resend undelivered emails.
If this keeps happening even though you send only a few emails a day, ask your Google Workspace admin to:
Check the Google Admin console for alerts or sending restrictions on your account.
Check whether other apps, devices, or tools are sending email from your account.
Contact Google Workspace support if the limit doesn't lift.
Google sets these limits, so Mixmax can't change or override them. To learn more, see Gmail sending rate limits for Sequences.