To warm up your new email account, you can simply begin by exchanging a few normal-looking emails with people you already know to indicate real-world usage. 

Then start sending a few cold emails (10-15) per day and eventually increase your volume to 40-50 emails per day by keeping a track of your email deliverability as well as the sender score. 

If it looks safe, keep gradually increasing the volume while monitoring the metrics to avoid damaging your email deliverability.