Slow Email Sending with 2.3.0.2

My host allows a maximum of 250 emails per hour so I can't use the built in Mail module to bulk send an email to all my customers as it tries to send out 1300+ emails in just a few minutes.

Is there an extension available that actually slows down the rate at which emails are sent out? ie. every 15 seconds instead of trying to do them all at once?

I don't care if it takes all day to send out the emails.

Thanks

Hi!
There is 3 ways (as I see):
1. Use specialized mail services for that
2. Use rabbitMQ - queue manager
3. Use cron extension with custom controller writed for this purposes.