I recently got a Samsung Insting from Spring and had go through all the hoops with Sprint and then Lunarpages to get this thing to work.
Here are my settings for the Instinct:
I chose Other Pop
email - my full email - XXXX@XXXXX.com
password - your email password that you use in webmail or Outlook
Incoming Mail Server - mine was janus.lunarpages.com. Yours may be different, you can find this when you log into Lunarpages.com
Port - 110
SSL - OFF
Account Name - your email address like xxxx@xxxx.com This was where I was messing up.
Outgoing Mail Server - same as incoming
Port - 25 or it may be 587
SSL - Off
SMTP Auth - ON
Name - This is just a title field in the phone. Just name it what ever you like. I put in "Company Email".

Hope everyone else has a better experience with this phone than I have so far.