The Outbox lets you view all your scheduled sequences, emails, reminders, and calendar events in one place. You can quickly search, edit, and reschedule any outgoing message or reminder from your Outbox.

To get to your Outbox, use this link or hover over the Mixmax "M" in the top right corner of Gmail and click Outbox:

You can reschedule an email or multiple emails in your Outbox at once. Check the boxes on the left for the emails you want to reschedule, and then hover over Reschedule to change the times for those items. You can even stop scheduled items using that same process. The Outbox shows 50 emails per page, so you can select up to 50 at a time. To reschedule more, go to the next page and repeat.

The panel on the left lets you filter the Outbox by event type.

If you're on a Workspace Team in Mixmax, the Team Outbox lets you see all the messages, sequences, and tasks you and your teammates have scheduled. You can switch between Teams using the tabs at the top of the Outbox.