Rotate emails to overcome 300 messages per hour?


I am searching for a low cost solution for sending automated emails from a couple of Moodle e-learning platforms (registrations, assignments, messages from teachers etc). Most of the time 300 emails per hour per email address should be fine, but I can’t predict if for example 5 teachers decide to send notifications to all their classes during the same hour.

My question is:

Is it allowed to rotate email addresses, so if one email address reaches near 300 email/hour I just switch it with another that has not been used lately? It would be some kind of fail safe mechanism, not something that would be in constant use. Most of the time there would be only zero to few messages per hour.

While you’re welcome to split up your email accounts by purpose, please don’t use additional email accounts for the sole purpose of bypassing the 300 per hour limit.

I guess than it would be ok if I open an email account for every teacher and than tweak the application to send email from teachers email instead of sending from one email account for all teachers.