I have two separate email addresses for my two Etsy shops. It's required. It's very frustrating for me because I hate logging in to all my emails! (I have 2 business emails and one personal, lol)
If you would like to have two emails linked together, here is what I did to roll my two business emails together. You might find this useful. I only had Yahoo until today, so I don't know how this would work with other email services. I think this can be done with Outlook and MSN, but I didn't check because I don't have email through them.
Only Gmail will forward to Yahoo. If you want Yahoo to forward to Yahoo or Gmail you have to buy an account.
I have my yahoo email as my main email service, it's on all my business cards and communications. But online venues require different email addresses for each shop. And, as I said, Yahoo requires a paid account to forward email.
1. I created a GMail account and used this as my contact email for notifications of messages and purchases for my secondary Etsy shop.
2. In GMail, you can go here to learn how forward your Gmail to your Yahoo.
Now, all my emails will automatically be forwarded from my Gmail to my Yahoo address, and no more logging into a second email account. Now I can close my other email down, and I only need to log into my one business email. Although I would suggest you log in at least once a week and make sure it is forwarding.
Hope this helps!