is there software that makes it possible to see another users information?

Question

I need somehting to help me check sent e-mails, pictures, recieved mail, etc. Anything that will help research the the other user's files.

Answer 1

There are 2 ways you could approach this, I recommend the first:
1. Ask them
2. Try a keylogging program that logs every keystroke and and gives information in which program it occured. a good one is Family Keylogger from www.spyarsenal.com/

Answer 2

There is.

But this is commonly known as "hacking", and in many places is very illegal.

There have been many instances of emails transmitting trojan viruses which compromise the target user's computer and convey the user's personal info to the hacker.

This is why we have such things as firewalls and anti-virus programmes.

You would be well advised to avoid such conduct.