outlook 2003 & 2007 Tags: Windows 7 Outlook 2003 Last response: May 20, 2013 12:55 PM in Windows 7 Share Yamaguchi May 20, 2013 12:26:15 PM guys while I am the only person in my household with this error code, I would truly appreciate an easy solution to outlooks error code 550. Anyone with info pls respond. Thanks in advance..... Sorry for my lame request guys, here is one of the thousands of responses that I receive as if I were initiating messages to these persons: [Return Code 550] sid: doxT1l0091NDzRC01 :: 5.1.1 unknown or illegal alias: firstname.lastname@example.org More about : outlook 2003 2007 noidea_77 a b $ Windows 7 May 20, 2013 12:36:42 PM Because your description is very unspecific and you don't even mention, when the error occurs, i recommend searching for "outlook error code 550" on google. There are a lot of hits and one may be related to your problem. ex_bubblehead a b $ Windows 7 May 20, 2013 12:55:37 PM Start here: http://office.microsoft.com/en-us/outlook-help/troubles... Then do a complete malware/virus scan of your PC as it may have become part of a botnet. Can't find your answer ? Ask ! Publish Related resources: Forumlock microsoft outlook 2003/2007 add email account? ForumSolvedUnderline Not Working in Outlook 2007 ForumSolvedOutlook 2003 corrupted in Windows XP ForumOutlook 2007 Duplicating Emails ForumSolvedOutlook 2003/XP E-Mails To Wrong Folders ForumSolvedMigrating Outlook 2007 to 2010 ForumI can't change the default browser in outlook 2007 ForumOutlook 2007 sunfolders missing ForumOutlook 2007 Profilename.xml ForumSolvedOutlook 2003 SP3 takes 15-25 seconds to open Forumoutlook 2007 will not open ForumCan't attach files in Outlook 2007 ForumCan't attach files in Outlook 2007 Forumoutlook 2007 stop working and restart by itself when i add new contact ForumHow do I sync an HP 210 Pocket PC with MS Outlook 2007 in Win 8 Forumi dont know how to strat outlook in ms office 2007 in win7.please give the solution me. ForumMS Office Pro Outlook2003 ForumOutlook 2003 sends mail but cannot receive mail ForumSolvedOutlook 2003 works intermittently on Windows 7 ForumThis one is going to take an expert Win7/IE8/Outlook2007 More resources Read discussions in other Windows 7 categories Configuration Customization Drivers Security Laptops !