Bug 948580 - [B2G][Email] Send "MAIL FROM" in SMTP probe to validate e-mail address.
GELAM changes included here.
GELAM changes for RCPT TO
Merge pull request #15951 from mcav/smtp-mail-from

Bug 948580 - [B2G][Email] Send "MAIL FROM" in SMTP probe to validate e-mail address. r=asuth