I saw that for the Windows plan you give unlimited email addresses. Does each account I create have a specific quota? Can I adjust that quota? Thanks!

This quota is included to your disk space quota.
That's all.

So if I have 30 email accounts each of them can be using 50MB at one time no problem assuming that amount (1.5GB) plus the amount of data in the web folders don't add up to more than my disk quota?

It is critical in case when real size of all your email is larger than your total disk account quota. You can overuse quotas but not not size

I'm afraid I don't fully understand. My case was a bit of an exaggeration for sure, but I need to be clear on the email details. Does each account get a quota? "This quota is included to your disk space quota" does not fully make sense. I'm "guessing" that this means each account does NOT have a quota and the total space that ALL the email accounts are requiring at a given time is limited by the total disk quota I have with particular plan? Thanks.

Each email account qouta is included in your total account quota. You may set up email quota or not. It is usable when you want to limit a size of mailbox of your clients.