I know students keep odd hours but 01:30 and working, and British - doubt it......
Pats is right to point out that a key aprt of your system design is interfacing the SMS system into you applciaiton then the choice of database is fairly arbitary at present.
The key iussue is how you expect to receive and decode the messages from your SMS server. There are several propriatory interfaces that coudl do this - some of the mobile manufacturers (Nokia & Motorola even have SMS interface APIS's). I suppose it depends on volume of SMS messages you expect.
A possible design strategy is to black box the SMS server and specify a required format for it to deliver data to your applicaiton, another is to talk to the phone directly. I have interfaced a phone connected to a PC via PHP scripts, I also use a Microsoft OS smartphone. All 3 phones are relatively easy to talk to. In principle the Samrtphone can be manipulated in exactly the same manner as an outlook folder - this may well be worth investigating.
The problem is that Access isn't neccesarily the best solution to do the interfacing to the phone, unless you have a Microsoft OS basaed phone. Its fine if you want a RAD to generate a "pretty" interface, but it can be a beggar to interface to hardware directly - for that reason I often resort to a quick & dirty VB6/
VB.NET program.
So it may be that you need to break down the application into 3 stages
1) data capture - either hardware or software interface to stripp off the data
2) dumping data into your db (this could be amalgamated with step 1)
3) reporting & MIS
Access is fine for step 3, given a choice I wouldn't use it for step 1. Depending on your experience and knowledge Access could be a resaonable choice - however if you are used to other RAD tools then these could be just as effective.
As Pat.P. says in order to help further you need to provide more information.