Mailstand allows users to have as many inboxes as they want on any given campaign. Each mailbox that you sync to the platform we will ask your for the specific mailbox's settings(ex: don't send more then 200 emails per day and space the emails apart every 2 minutes). Once the mailbox is set, we then look at the campaign settings. Our sending algorithm looks at both settings and determines when to send and from what mailbox.
We also have cool logic in place that locks a mailbox to a particular prospect/contact so that each follow up email comes from the same email address for consistency.
If we're being honest, this feature and complex sending schedule does not exist anywhere else in the world. We spent over a year building this feature. You can learn more about our value proposition and difference in our manifesto