SMTP HTTP HTTP CONNECT HTTP proxy # Server-side HTTP/1.1 200 Mighty fine indeed smtp: sure hit me # Client-side smtp http-proxy http proxy SMTP send tunneled through HTTP proxy From: different To: another body smtp://smtp.%TESTNUMBER:%SMTPPORT/%TESTNUMBER --mail-rcpt recipient@example.com --mail-from sender@example.com -T - -p -x %HOSTIP:%PROXYPORT # Verify data after the test has been "shot" EHLO %TESTNUMBER MAIL FROM:%LTsender@example.com%GT RCPT TO:%LTrecipient@example.com%GT DATA QUIT From: different To: another body . CONNECT smtp.%TESTNUMBER:%SMTPPORT HTTP/1.1 Host: smtp.%TESTNUMBER:%SMTPPORT User-Agent: curl/%VERSION Proxy-Connection: Keep-Alive