EDIFACT EDI System

Hi my name is John and my first post here on your Site and I hope that I have the right area, If not please correct me.

I currently use Filemaker 12 Pro Advanced and will include Filemaker 12 Pro Advanced Server in the very near future. I am looking to create an online entry form system using EDIFACT EDI messaging to communicate with certain EDI agencies using pop3 mailboxes.

I am expected to support Windows / Mac and Mobile devices for the entry side of things and host the data on a webserver which will connect directly with all clients regardless of O/S.The entry form side of things I have sorted out, the layouts etc..and I am expecting to output the data into messages first as XML. then convert them to EDIFACT EDI which will then be forwarded onto the organization for processing, then process the replies in the reverse order.    Eg: Form - XML - EDIFACT then EDIFACT - XML back to Form entry using pure pop3 mailboxes. The reason for the dramatic change is that the database software currently being used is older than Noah, and I want to give users a cleaner unclutered interface with a more modern feel and look while capturing future potential clients on other operating systems that I do not currently support (Mac & Mobile Devices).

I understand the EDIFACT format  segments, DTMs PNA, etc and have the tools to map EDIFACT to XML files backwards and forwards and can easily parse messages on demand.

My question to everyone, has this been done in Filemaker before? and what are the pros and cons to this approach I am attempting to take on. I do not expect to support more than 250 users at a given time which I think is very realistic approach on the intended application. Your thoughts please!!

With Many thanks John