Dear All

In our exchange 2013  enviroemnt  some of the external users complains that their email got bounced  with following error message

550 5.7.1 Requested action not taken: message refused.

What may be reason.?

It happening only  for few users.

Kindly advice please.

There is some content filtering on your end blocking these emails
Check the logs on your GW filters, Antispam filters and check your exchange content filters

Also check  who is the NDR generating server

MOst likely there must be some filtering on your end which is causing this issue

Hi Ashraf,

Thank you for your question.

Did all emails get bound for the specific user?

Did the email include the specific word or sentence?

The error means the Exchange server refuse the message to deliver to internal, we could check if there are any transport rules or filter in Exchange server (include the Edge server), as Sathishs said.

In addition Sathishs suggestion, we could check if there are third party software in organization to block email, for example Symantec Mail or others. We could rebuild the Edge subscription to check if the issue persist.

We could also refer to the following links:

http://blogs.technet.com/b/jhoward/archive/2005/10/11/412328.aspx

https://social.technet.microsoft.com/Forums/exchange/en-US/fc36bdf9-1e50-447f-81fe-e626e3040af2/571-smtp550-571-message-rejected-as-spam-by-content-filtering-smtp?forum=exchangesvrsecuremessaginglegacy

If there are any questions regarding this issue, please be free to let me know.

Best Regard,

Jim

In addition to Sathish & Jim below are some steps:

A very common Exchange 2010 NDR, the cause is a permissions problem.  For some reason the sender is not allowed to email this account.
Perhaps an anonymous user is trying to send mail to a distribution list.
Alternatively, a user may have a manually created email address that does not match a System Policy.
Check SMTP Virtual Server Access Tab.  Try checking this box: Allow computers which successfully authenticate to relay.
Check the outgoing SMTP logs.
Check: Mailbox <Mailboxname> Properties Mail Flow Settings Message delivery restrictions.
Try disabling Windows-Integrated-Security.  Instead allow only standard authorization on the SMTP receiver on the Exchange 2010 server.

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