As companies grow their email list, they typically start out with a small business email platform such as Constant Contact or Mailchimp. The starter packages at with these email vendors place you on a shared server, but as your list grows you may need to move on to an up-graded account, or you may decide to get your own dedicated server. Once you are ready to move over to a dedicated server you have to move slowly, as your mistakes will immediately impact your deliverability success.
Warming up IPs is very important to get your content delivered. If you think that you can send 200K emails using brand new IPs you are in for a shock. ESPs are not going to let you ruin their IPs by blasting. You’ve got to start slow, prove that you can deliver and engage with a small portion of your list, then mail to a little more, growing little by little until you have proven that you are a quality emailer who does not send spam.
IPs start out with no reputation at all, and are referred to as being cold. If you encounter hard bounces or spam complaints the reputation goes down. If you successfully send mail to engaging subscribers then the reputation goes up. Sending a lot of mail using IPs with no reputation is as bad as sending with bad reputation. Those emails are not going to reach their destination. Once, you have a bad reputation it is extremely difficult to rebuild.
Think of a criminal, once they get caught doing something bad and it goes on their record. It then makes it hard for them to find employment or get people to trust them. It takes time and recommendations for them to be able to get back to a more functional lifestyle. Same with your IPs, once you get too much bad rep they cannot do their job of successful delivery. Then, it is time to give up that IP address and try again.
Warm up your IPs slowly. Make sure your list is Opt-in and cleaned. If you want to send daily mail, you will need to start out at 1000 the first day. If that went well you can send 2000 the next day, and so on until your reputation is good enough to send out large quantities of email. If you send out too fast too soon your emails will get delayed or may not be delivered at all.