FAX problems, missing data on the BP

Hi Experts,

We are working in SRm 4.0, extended classic senario.

I have made some settings for sending a PO, from SRM, by FAX, and I can get a FAX out of SRM, by using force?

I have some vendor's to whom we would like to send PO's by FAX. Where do I make the settings on these vendores? I have activated the field 'standardComm. Mtd' on the BP, whith the value 'FAX fax'. If I then look into the BP from the WEB by using transaction 'manage business partner', the field 'Standard Communications Protocol ' is blank. Which value shall I activate in this field?

I have the following oppertunities:

1.Marketplace communication.

2.Send to FTP server.

3.Send to HTTP server.

4.Send to HTTP server (HTTPS).

5.Send via E-MAIL.

Best regards Kim