Voicemail to Text Transcription service - repost

I"m not sure what language to use. We need a program that will transcribe a voicemail (.wav file) to text and send it back via email with the text in the email and the .wav file attached. One suggestion would be to utilize AT&T's Speech to Text API which is described here: [login to view URL] I don't want to use Nuance. We will send the email with the attached .wav file to the program which will know according to the email we are sending it to where to send the transcription. For example, our PBX system will send an email to: xxx (at) transcriptionprogram (dot) com and the program will know that xxx corresponds to => that person in the database and will transcribe the voicemail and send the email to the persons email address in the database with the .wav file as an attachment. We should be able to add addresses to a portal i.e.: First Name, Last Name, Email Address, Unique id (i.e. xxx above). We are a VoIP hosted PBX company and we want this to be hosted either on a Windows but preferably a Linux Server.