SMTP SMTP HELO RFC821 # # Server-side REPLY EHLO 500 Command unrecognized REPLY HELO 250 Already old but still servicing... # # Client-side smtp RFC821-only SMTP server (EHLO not supported) From: different To: another body smtp://%HOSTIP:%SMTPPORT/user --mail-rcpt 804@foo --mail-from 804@from -T - # # Verify data after the test has been "shot" EHLO user HELO user MAIL FROM:804@from RCPT TO:<804@foo> DATA QUIT From: different To: another body .