cannot send to some receipients with error "550-Please turn on SMTP Authentication in your mail client" RRS feed

  • Question

  • I am using exchange 2003 connected using MAPI with outlook2010.

    when i send e-mail to one of my customer.

    i got below error message

    There was a SMTP communication problem with the recipient’s email server.  Please contact your system administrator.

    < #5.5.0 smtp;550-Please turn on SMTP Authentication in

    your mail client. > was my server

    and my customer was using messagelabs "" to receive mail

    i was strange that MAPI connect does not need smtp authentication when send out e-mail.

    is that anythings i have missing to do?

    thank you

    • Edited by try and try Monday, January 13, 2014 5:07 AM
    Monday, January 13, 2014 5:05 AM

All replies

  • Hello,

    Kindly go through with below link.

    Deepak Kotian.

    MCP, MCTS, MCITP Server / Exchange 2010 Ent. Administrator

    Disclaimer: Please take a moment to "Vote as Helpful" and/or "Mark as Answer", where applicable.
    This helps the community, keeps the forums tidy, and recognizes useful contributions. Thanks!

    All the opinions expressed here is mine. This posting is provided "AS IS" with no warranties or guarantees and confers no rights.

    Monday, January 13, 2014 5:54 AM
  • Hi,

    For this issue, here are some suggestions below.

    1. Please make sure your domain is not in the blacklist.

    2. Do you use smarthost to send outbound emails?
    If you use smarthost to send emails, I recommend you check Basic Authentication. Go to SMTP connector on the Advanced tab, click on Outbound Security and click Basic Authentication. If not, besides the SMTP Authentication, please make sure the MX record is created correctly.

    3. Could you send emails to another domains successfully?
    If all domains are affected, please check the SMTP connector to see if it is configured correctly. You can try to recreate a new SMTP connector to check the result. If only one domain, please check step 1.

    By the way, since Exchange 2003 is old Exchange version, we have not supported for Exchange 2003. I recommend you upgrade Exchange 2003.

    Best regards,

    Belinda Ma
    TechNet Community Support

    Wednesday, January 15, 2014 2:41 AM
  • Dear Deepak Kotian - Ratish,

    Your links are bounded- "This solution is available to Premium Members".

    Why don't You just answer the question in this thread instead of putting such links to community of Premium Members? I will not dare to become a Premium Member just for the moment in order to check if this is the exact answer I need.

    Thank You.

    “The sublimity of wisdom is to do those things living, which are to be desired when dying.”
    George Norman Douglas

    • Edited by without_nic Wednesday, October 1, 2014 10:08 AM
    Wednesday, October 1, 2014 9:52 AM
  • Just some comments:

    I don't think this message would be due to being on a blacklist but... to rule it out, you can use the blacklist test here:


    The MX records would not come into play for sending messages - if they are configured incorrectly, that could prevent *receiving* messages however.


    Otherwise, can you confirm that the *same sender* can send to recipients in well-known domains like gmail or Hotmail? Is this the *only* recipient that returns this error message?

    In your title you say "some" but later you write "one of my customers".

    That would make a difference (if there is only one recipient out of many with this problem).

    Please mark as helpful if you find my contribution useful or as an answer if it does answer your question. That will encourage me - and others - to take time out to help you.

    Thursday, October 2, 2014 12:01 AM
  • Hello,

    Provided link was not only for Premium Member. Anybody can access these link.

    Monday, October 6, 2014 10:30 AM