Undead and using Detect Thoughts

[Bellberith]

Can an undead character use detect thoughts to detect other peoples thoughts. even though he is immune to mind effecting effects?

Also, if he uses a medallion of thought projection (cursed) would the curse work on him since it is mind-affecting.

[Alex12]

Can an undead character use detect thoughts to detect other peoples thoughts. even though he is immune to mind effecting effects?

Also, if he uses a medallion of thought projection (cursed) would the curse work on him since it is mind-affecting.

I assumed the detection is the part that's mind-affecting, not the part that provides the undead with the information. So an undead wizard could Detect Thoughts as easily as a living wizard, but wouldn't be picked up by same.
I'd assume the medallion wouldn't work, and the interaction between voluntary telepathic contact and undead is a bit unclear, IIRC.