OSX server invitation and automatic configuration

I am setting up my OSX 10.6 Server on my Mac Mini. When setting up the mail account, using MAIL and configuring my address on my Mac book pro running OSX 10.8 I get the above screen.

When I pressed automatic configuration a screen came up asking me to choose and application. I choose MAIL and then ticked the box that says "always use this application". Unfortunately the MAIL application did not work and now I can not try another app to automatically configure my MAIL.

Can someone please advise me where im my files I can find this string so that I can delete the "always use this application" bit, to allow me to continue with my set up.

I have tried to search for this problem on line but just can not find anyone who has done something similar. Mind you I am probably using the wrong terminology. Below I have details of my computer and software.

Many thanks

Model Name: MacBook Pro

Model Identifier: MacBookPro9,1

Processor Name: Intel Core i7

Processor Speed: 2.6 GHz

Number of Processors: 1

Total Number of Cores: 4

L2 Cache (per Core): 256 KB

L3 Cache: 6 MB

Memory: 8 GB

Boot ROM Version: MBP91.00D3.B08

SMC Version (system): 2.1f170

Serial Number (system): C02HN01SDV35

Hardware UUID: 01641B61-511A-5D19-A8C1-0FADEBA8FFCB

Sudden Motion Sensor:

State: Enabled

System Software Overview:

System Version: OS X 10.8.2 (12C3012)

Kernel Version: Darwin 12.2.1

Boot Volume: Macintosh HD

Boot Mode: Normal

Secure Virtual Memory: Enabled

Time since boot: 11:46