This uses a wireless connection so you could link your phone to it via WiFi (or possibly bluetooth) and be able to use the internet on your phone. There are no monthly fees or contracts involved.
fiery1, I'm not exactly sure if I'm understanding what you are asking or not.
First, this card only supplies service to the Straight Talk WiFi Mobile Hotspot which you first have to purchase for $79 (copy-and-paste):
Once you have applied this card to the hotspot, the hotspot will supply a wi-fi source that you can use to wirelessly connect to the internet from your smartphone, laptop, tablet, etc.
If you have your smartphone connected to the hotspot (wirelessly), yes, you can check your email but remember, you will have to carry around the hotspot with your smartphone which could get cumbersome.
Secondly, I'm not sure why you are mentioning a Straight Talk cell phone plan that has unlimited talk and text but NO data (web) as no such plan exists. Both Straight Talk Unlimited Plans will have data/web included (with a 2.5 GB soft-cap). Those plans will be monthly or every 30-days in duration with not rollover.
Hotspot Plans like this one are also monthly or good for 30-days (the the 4, 5, and 7 GB cards being good for 60-days) or whenever the data is used up whichever comes first with no rollover if data remains after 30-days (or 60-days on the larger cards).
The Straight Talk WiFi Mobile HotSpot is primarily intended for those on the go (so that they can carry the hotspot with them) in order to supply an internet connection (wi-fi) for light usage so that they can have their own personal wi-fi source for their laptop, tablet, iPad, etc. rather than having to hunt for a public wi-fi source such as Starbucks, library, hotel, airport, etc.
Am I making sense or am I misinterpreting what you are asking?