2007 Outlook error code: 0x800CCC78


  • HELP!!!!

    I use Outlook 2007 to access my email (AOL).  Out of the blue it started acting up two days ago.  I am able to receive messages, the problem is when I try to send a message.  I'm receiving an error message:   "Sending reported error 0x800CCC78. Cannot send the message. Verify the e-mail address in your account properties.  The server responded 554 5.7.1. Sender address rejected. Access denied."  I have not added/deleted any programs or files.  Is anyone else having this issue?  Any help would be greatly appreciated!!!!!
    Monday, February 22, 2010 6:26 PM


All replies

  • Dana is not alone, my Outlook suddenly decided it would not send e-mails (error 0x800CCC78) I have scoured the forums, etc and this is obviously a VERY COMMON problem for which Microsoft clearly DO NOT HAVE AN ANSWER.  Suggestions to change the SMTP port to 587 are very helpful, if only that solved the problem!!

    Anyone know the answer, as Microsoft don't appear to.
    Wednesday, March 17, 2010 4:03 PM



    Thank you for visiting the Microsoft forum. This forum focuses on Perfmon and diagnostic tools. I am moving your question to the moderator forum ("Where is the forum for..?"). The owner of the forum will direct you to a right forum.



    Bruce Adamczak

    Friday, May 07, 2010 3:07 PM
  • Try asking at


    Ed Price (a.k.a User Ed), SQL Server Experience Program Manager (Blog, Twitter, Wiki)

    Saturday, June 09, 2012 6:10 AM