Event ID - 3018

Event Id3018
SourceMSExchangeActiveSyncNotify
DescriptionA non-delivery report with a status code of number was generated for recipient proxy address (Message-ID id).
Event InformationAccording to Microsoft:
Cause:

This event is logged when a non-delivery report is generated because of a problem with DNS or an IP address. The numeric code is generally 5.4.0. This indicates that an "Authoritative Host was not found".
Resolution:
Check the DNS using nslookup or dnsq. Verify the IP address is in IPv4 literal format.
User Action :
To resolve this error, try one or more of the following:
Use the command line tool NSlookup to verify that DNS is correctly configured. For example, make sure that the target domain can be resolved. Additionally, make sure that an MX or A record can be found.For information about how to use NSlookup, see article Q200525.
Verify that the IP Address is in IPv4 literal format.
Verify that an overriding fully-qualified domain name or hosts name is not present in the HOSTS file on this Exchange server.
Reference LinksA non-delivery report with a status code of number was generated for recipient proxy address

Q200525:Using NSlookup.exe

Catch threats immediately

We work side-by-side with you to rapidly detect cyberthreats
and thwart attacks before they cause damage.

See what we caught

Did this information help you to resolve the problem?

Yes: My problem was resolved.
No: The information was not helpful / Partially helpful.