If you just started with email marketing or switched your delivery provider or even our domain or IP address it’s a good practice to not start blasting your provider with to many emails at once.
With Mailster you can slowly increase your mail through put over time.
If you start fresh you should consider taking a one month warm up period. Mailster will adjust the send rate according to your setting and increase the mails which are sent in a batch.
This option works even better if you enable automatic calculated batch size.