There was a SMTP communication problem with the recipient's email server

Posted on 2007-08-03
Last Modified: 2013-11-30
All outgoing emails fail with:
Your message did not reach some or all of the intended recipients.

      Subject:      test
      Sent:      03/08/2007 12:26

The following recipient(s) could not be reached: on 03/08/2007 12:26
            There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.
            < #5.5.0 smtp; ( [] is currently not>

Stopped working about a week ago. No idea what changed. Incoming email ok. Can send using Outlook Express to (same mail server) so domain host seems ok.
I've rummaged around on EE re similar messages and looked at some solutions, but no luck. ESM Recipient Policies show, not .local.
The isp say it is not a reverse dns problem. FQDN is set to our domain, They are sure it is a exchange problem at our end.

Help much appreciated!
Question by:DSL8159
    LVL 104

    Accepted Solution

    Is Demon Internet your ISP?
    If so you have my deepest sympathy.

    Anyway, the server you are sending your email out through is rejecting your message. If that server is not Demon's server then you need to adjust the SMTP Connector to authenticate when sending email.
    ESM, Connectors. Right click on the SBS SMTP Connector and choose properties.
    Click on the tab Advanced and then Outbound Security. Enter the username and password required by the operator of the server you send email through in to the box. Apply/OK out.

    The reason it works in Outlook Express is that you have probably configured it with an account that checks POP3 first. Most ISP email servers will then allow you to send if you check your email first. Exchange cannot do that.

    LVL 7

    Expert Comment

    If the incoming mail is being directed to (where your A & MX records are pointing) could this not be a result of the origin IP not matching the domain of the return address ( Have you changed anything on the public IP side of things?


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