However, with the rise of modern cloud computing, this IP thing meant very little unless you wanted to run your own private mail server or send emails from your machine, which no one in their right mind would do these days.
Note: It is still relevant if you purchase a private IP to send emails using an existing sending provider like SendGrid. But even there, SendGrid will monitor your sender reputation and simply kick you off their service if it drops too much.
If you are using G Suite (Gmail), you are unknowingly using Google IP addresses when sending emails. And if you are using Office365/Outlook, you are using Microsoft IP addresses. So who cares about warming up IPs, right?
Well, it turns out that for ESPs (email service providers, like Gmail bahrain mobile database and Outlook, to name the major ones), it is still very relevant because they are the ones who manage the server IPs to deliver your emails. The last thing they want is for a user to destroy their IP addresses by sending spam messages.
And so, each ESP began implementing its own sender reputation system to protect its system from user abuse.
And since there is no standard for this, your sender reputation will depend on which ESP you are using.
Unfortunately for us cold email users, the factors used to determine sender reputation are not shared publicly, but finding the most important ones is not that difficult through trial and error.
Here are 3 strong factors that you cannot afford to ruin:
Your bounce rate: A high bounce rate (sending emails to addresses that don't exist) is a sign of mass mailing.
Your spam complaint rate – This is an indicator that you are sending spam emails.
Your engagement rate: The more people interact with your email, the better your sender reputation.
Here's the catch: Your reputation is rarely shared with you (certainly not in G Suite or Outlook), so you don't really know where you stand until it's too late.
Also, if you change your inbox provider, you won't be able to keep your good reputation (you will, however, keep your bad reputation since the big ESPs exchange information about abusers with each other).