Rein, I now get all the key exchanges at the beginning of the session so that is working fine. But, when trying to send emails with server 1.4.0a I get the error message below. The issue seems to be the <smtp_host> string. I have tried with smtpauthlevel at 1 too but I get the same result. I have also extracted the section of the pskmailrc.pl, file at the bottom. Regards, John 15:14 UTC Aug-24-2011: Receiving compressed mail Net::SMTP>>> Net::SMTP(2.31) Net::SMTP>>> Net::Cmd(2.29) Net::SMTP>>> Exporter(5.63) Net::SMTP>>> IO::Socket::INET(1.31) Net::SMTP>>> IO::Socket(1.31) Net::SMTP>>> IO::Handle(1.28) Net::SMTP=GLOB(0xa8576c0)<<< 220 mail01.syd.optusnet.com.au ESMTP Sendmail 8.13.1/8.13.1; Thu, 25 Aug 2011 01:14:08 +1000 Net::SMTP=GLOB(0xa8576c0)>>> EHLO localhost.localdomain Net::SMTP=GLOB(0xa8576c0)<<< 250-mail01.syd.optusnet.com.au Hello c122-106-179-89.blktn4.nsw.optusnet.com.au [122.106.179.89], pleased to meet you Net::SMTP=GLOB(0xa8576c0)<<< 250-ENHANCEDSTATUSCODES Net::SMTP=GLOB(0xa8576c0)<<< 250-PIPELINING Net::SMTP=GLOB(0xa8576c0)<<< 250-8BITMIME Net::SMTP=GLOB(0xa8576c0)<<< 250-SIZE 52428800 Net::SMTP=GLOB(0xa8576c0)<<< 250-DSN Net::SMTP=GLOB(0xa8576c0)<<< 250-ETRN Net::SMTP=GLOB(0xa8576c0)<<< 250-AUTH PLAIN LOGIN Net::SMTP=GLOB(0xa8576c0)<<< 250-STARTTLS Net::SMTP=GLOB(0xa8576c0)<<< 250-DELIVERBY Net::SMTP=GLOB(0xa8576c0)<<< 250 HELP 15:14 UTC Aug-24-2011: Connection open... Net::SMTP=GLOB(0xa8576c0)>>> MAIL FROM:<smtp_host> Net::SMTP=GLOB(0xa8576c0)<<< 250 2.1.0 <smtp_host>... Sender ok Net::SMTP=GLOB(0xa8576c0)>>> RCPT TO:<vk2eta@xxxxxxxxx> Net::SMTP=GLOB(0xa8576c0)<<< 553 5.5.4 <vk2eta@xxxxxxxxx>... Domain name required for sender address smtp_host Net::SMTP=GLOB(0xa8576c0)>>> DATA Net::SMTP=GLOB(0xa8576c0)<<< 503 5.0.0 Need RCPT (recipient) Net::SMTP=GLOB(0xa8576c0)>>> From: smtp_host Net::SMTP=GLOB(0xa8576c0)>>> Reply-To: smtp_host Net::SMTP=GLOB(0xa8576c0)>>> To: vk2eta@xxxxxxxxx Net::SMTP=GLOB(0xa8576c0)>>> Date: Thur, 25 Aug 2011 01:14:08 (EST) Net::SMTP=GLOB(0xa8576c0)>>> Subject: Test mail via new client Net::SMTP=GLOB(0xa8576c0)>>> Comments: Via PskMail. Net::SMTP=GLOB(0xa8576c0)>>> Net::SMTP=GLOB(0xa8576c0)>>> PSKmail message from smtp_host Net::SMTP=GLOB(0xa8576c0)>>> From: johndouyere@xxxxxxxxxxxxxxx Net::SMTP=GLOB(0xa8576c0)>>> test 1. Net::SMTP=GLOB(0xa8576c0)>>> . Net::SMTP=GLOB(0xa8576c0)<<< 500 5.5.1 Command unrecognized: "From: smtp_host" Net::SMTP=GLOB(0xa8576c0)>>> QUIT Net::SMTP=GLOB(0xa8576c0)<<< 500 5.5.1 Command unrecognized: "Reply-To: smtp_host" End of mail receive... $relay = "mail.optusnet.com.au"; $smtpauthlevel = 0; $smtptlsuser = "userid\@gmail.com"; $smtptlspass = "password"; $smtptlsport = 587;