Correct send mail function with Linux

1) Add the "from address" needed by SendMail in the settings
2) Correct a problem of strings translation in send mail function
Tested with Ubuntu 13.04 (and also Windows Vista & XP)
needs a correctly configured MTA
I tried SendMail but it is very complex to configure and I gave up.
I found sSMTP which is very easy to configure and works well.
Jean Pierre