I liked it, could be doing other and it would let me know without having to keep checking.
I have that now on my MacBookPro, you can click on that feature and it will let you know you have mail, but you have to leave the computer tuned to the mail service, which is fine if you are doing other than using the computer anyway.
I use Thunderbird for my email client and we did have it set up to make a noise when we got a new message. It didn't say "you've got mail" though, it made a thwack noise and said "message for you sir" - which is a sound byte from Monty Python and the Holy Grail. I do miss it. I'll have to speak to my network administrator, aka, my husband and get that noise back.
My e-mail client plays a tone when I get a new message. I haven't tried to configure it, but I'm quite sure that I could find that audio file and replace it with "You've got mail" if I really wanted to. Which I don't, because AOL sucks and always has
My mother still has AOL too. On top of her DSL from her company. I just don't get the reasoning there.
I also still have AOL and the reasoning, too hard to get everyone to use a new email.
I have a newer gmail account, that all AOL mail goes to by default also, so I have in reality two backup email accounts.
My problem, everyone kept sending my email to AOL anyway, so I gave up.
Some day I will quit using the AOL one and eventually all will learn that one is not my current one any more.