Add a reference FAXCOMEXLib.dll to your Webservice:
FAXCOMEXLib.FaxServer faxServer = new FAXCOMLib.FaxServerClass();
if (FaxNumber != "")
{
try
{
faxServer.Connect(MachineName);
faxServer.Retries = Retries;
faxServer.RetryDelay = RetryDelay;
FAXCOMEXLib.FaxDoc faxDoc = (FAXCOMEXLib.FaxDoc)faxServer.CreateDocument(FileName);
faxDoc.RecipientName = RecipientName;
faxDoc.FaxNumber = FaxNumber;
faxDoc.DisplayName = DocumentName;
int Response = faxDoc.Send();
success = true;
}
catch{}
finally
{
faxServer.Disconnect();
}
}