Im pretty sure the E is just telling you that it is running on the Edge network. The same network that the iPhone runs on. It isnt nearly as fast as 3G. But as far as your reception problem goes, I have found that there was a recall of sorts on phones made during a certain time frame that were not equipped with adequate antenna's. Mine was in this category and AT&T sent me a new phone. So as long as your phone meets the date requirements and hasnt ben broken, soaked or have a lot of significant damage they will replace it. Just read the info on this forum and call the number.
httpslash slash)gizmodo.com/gadgets/cellphones/samsung-official-response-on-blackjack-issues-326675.php

I had to botch the link up because I dont have enough posts to post straight links. But just the // is messed up.

I have had a blackjack for a while, and i have encountered a problem where i am in my house just sitting on my couch, and i can not recieve incoming calls, or make outgoing calls... i have atleast 3 bars of service so i dont see why i cant get/make calls.. but i noticed whenever this happens there is an E on the top of my phone instead of the 3G sign, does anyone know what this E means? and if its possible to fix my problem, it is my work phone and i am missing alot of calls because of this, not to mention when i called it from my house phone it will ring 3 times and go into voicemail as if i forwarded the call... except my blackjack does not ring at all and does not tell me that a call was made.. any help is greatly appreciated. thanks