How to modify PATH variable for X11 during log-in?

How do I find out the complete return-path of a sender in Yahoo Mail?

• I looked at this answer from 2002, but the method doesn't work [anymore] -- I just get the sender's email address in the "To" field, e.g., "To: [email protected]". http://answers.yahoo.com/question/index;_ylt=Ak5_Htt4UzvMVYefeeiy3tsjzKIX;_ylv=3?qid=20081028070317AAweL2e Back story: I visited a friend at "Company X", used friend's computer to log into my Yahoo Mail account, and corresponded with a potential buyer for an item I posted on a website. The person sounded fishy and wanted to pay electronically using an online payment service, even though my ad clearly stated cash only. He claimed to be associated with "Company X" where I was temporarily visiting, although I never mentioned "Company X" at all. It felt kind of creepy. It seems that the person looked at the full path my message took from "Company X" to get to him and claimed to be associated with "Company X" to build common ground and appear trustworthy. Uh, that didn't work. So now I'd like to see his full return-path to see if he even lives in the area, or is indeed a complete scammer. Thank you.

• Answer:

  Try this out: 1) Select the message so it shows on screen. 2) Above the message, click "Actions". 3) In the drop-down menu, click "View Full Header".