How do you erase all of the contacts names you ever email, when you never saved them to your contacts?

I dont think you can, I think they stay there forever.

Will they erase if I restore my iPod?

Why would you restore it just for that? No.

Can anyone else be helpful?

Google Chrome has an auto fill feature, and it made me mad when it saved my credit card numbers. When the box pops up below where you’re typing, try pressing down (to select whatever) and then delete. That’s what worked in Chrome, but Chrome and an email client is different. I tried it in Gmail, and it doesn’t work. I had to go to my contacts and delete the person (even though I never added her) to keep her from showing up. I just started typing what I had been typing in the search bar to bring up whoever I didn’t want to be there.