Hi there, I'm having outbound SMTP communication problems with a few select external Exchange email servers. When my Exchange server tries to pass an email via SMTP to these external companies I get an error message "421 5.5.2 syntax commandline too long". My Exchange server is Ex 2k SP3. This also happened with another company a couple of weeks ago, they uninstalled their ISA and suddenly it started working again, Not sure if it's a coincidence. The company I'm currently having difficulties sending emails to, say they are using ISA as well as a Gateway MailFilterer product. Plse help - here are the SMTP logs. 2005-06-30 12:04:24 210.54.1.82 OutboundConnectionResponse SMTPSVC1 MyMailServer - 25 - - 220+ClientsMailServer+Microsoft+ESMTP+MAIL+Service,+Version:+6.0.3790.1830+ready+at++Fri,+1+Jul+2005+00:04:17++1200+ 0 0 122 0 31 SMTP - - - - 2005-06-30 12:04:24 210.54.1.82 OutboundConnectionCommand SMTPSVC1 MyMailServer - 25 EHLO - ClientsMailServer 0 0 4 0 31 SMTP - - - - 2005-06-30 12:04:24 210.54.1.82 OutboundConnectionResponse SMTPSVC1 MyMailServer - 25 - - 421+5.5.2+Syntax+error+(command+line+too+long) 0 0 46 0 47 SMTP - - - - 2005-06-30 12:04:24 210.54.1.82 OutboundConnectionCommand SMTPSVC1 MyMailServer - 25 QUIT - - 0 0 4 0 47 SMTP - - - -
