#5.5.0 smtp;550 Blocked Share on Facebook Post on reddit Tweet on Twitter Share on LinkedIn Home › Forums › Messaging Software › Exchange 2000 / 2003 › #5.5.0 smtp;550 Blocked This topic has 2 replies, 3 voices, and was last updated 12 years, 11 months ago by louisvillecat. Viewing 1 post (of 1 total) Author Posts altaancMember Oct 30, 2007 at 10:20 am #128549 Some people are getting the error below when they are trying to send us email through a form on our website. The website is running Windows 2003 R2 and we are using Exchange server 2003. The error is: There was a SMTP communication problem with the recipient’s email server. Please contact your system administrator. Any help will be greatly appreciated. Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic.