DVD won't play/Mail lost

[zzzuppp]

1)I bought a burnt DVD which will play quite happily on a PC but won't even mount the disc image in the DVD player of my OSX 10.1.5.The seller sent me another copy-just the same.Is there anything I can do?I don't want to find a PC every time I want to see it..can I get a more friendly copy? I thought anything would open in the DVD player of a Mac.

2) Mail has disappeared from my dock and Apps.I guess someone may have inadvertently Trashed it.Can I get it back? Or do I have to reinstall everything-in which case how do I save any Apps that I've added or downloaded?

[mklos]

People aren't gonna help you play something pirated! As far as your Mail app goes, well unless you have another Mac or a friend with a Mac to give you the Mail.app back to you, you're basically screwed and will have to reinstall Mac OS X to get it back.

[zzzuppp]

Um,this one is legal,mklos,it's a friend's own movie. :)