Outlook Error 550 - Version 3.4 If you are using Outlook extensively as an email client application then Outlook error 550 is not a new thing for you. Through outlook recovery, you can quickly send, receive, store, and move your any data mails to other person. Sometimes, you face many difficulties with Outlook application. Suppose you are using it for long times and suddenly your PST file get corrupted due to virus attack etc. So, get our Outlook recovery software v3.4 to recover Outlook data of 64 bit of all the Outlook versions like Outlook 2002, 2007 and 2010 etc.Outlook error 550 - Are you facing Outlook error 550 on screen “Your message did not reach some or all of the intended recipients. Subject: RE: trying to send this again... Sent: [Date] [time] the following recipient(s) could not be reached: 'Recipient _name' on [Date] [time] 550 sorry, that domain isn't in my list of allowed rcpthosts (#5.4.3) “And this error messages has showed due to sending emails, improper software installations etc. You can