Is AppleSupport@InsideApple.apple.com a genuine Apple email address?

No.

It's a scam ...

Help here > Identify and report phishing emails and other suspicious messages - Apple Support

apple.com is genuine, but that email can be faked very easily.

if links in the email show green text in Safari then the site is legitmate

example:

insideapple.apple.com is legitimate; if its where the address actually resolves to

the last word between the last "." and the ".com" is the domain

.apple.com is apple (and appears to be what you were sent)

if you saw

.apple.insideapple.com it would not be apple

the question is where does this resolve to. scammers may put in legit links and then have the one you click completely fake. You can roll over the links and see where the go on the lower left hand side of the open window of your web browser or email client.

example

www.apple.com

easily forged.