I run a small startup and am in the process of hiring more sales folks and understanding how to warm a separate email domain. Need some advice.

I've been searching on Google for like 45 minutes with no real answer, so thought one of you might know.

We have our main company domain and have been using HubSpot Sales Pro for the last few years.

We have been doing founder led sales this whole time and have had no issues with our email domain reputation (i think?). I mean, I'm still getting sales, so that's all that matters.As I think about hiring new folks, I have been told to create a separate email domain to use specifically for sales. We have a .com and bought a very similar domain name with a .co

So, for you Sales Gurus that use HubSpot, how do I go about adding the new domain under our main company account?

For example, if I want to continue to partake in sending cold outreach, should I add that new domain under my main email inbox as an Alias or should I treat it as a secondary email?

Any suggestions on how to handle that? I'd prefer to have everything come into one inbox and just be able to switch between the accounts as needed.

And yes, once that is set up, i know I need to warm the new email up and what not, make sure DMARC and all of those settings are good. I'm mainly curious as to how most of you have things set up within HubSpot to make it as easy as possible.

Thanks for the help!