Cannot resolve certain DNS name

[irfan.hendriana]

Hi,

i'm stuck this error. i can resolve any domain name from my cisco ironport, but whe we send email to office 365 which is the smtp gateway like domain.mail.protection.outlook.com, the message always queue delivery and bounce back like bellow. when I check diagnostic, the domain.mail.protection.outlook.com cannot be resolve.

#< #5.0.0 smtp; 5.4.7 - Delivery expired (message too old) 'Multiple DNS queries were attempted and failed: DNS Soft Error looking up domain.mail.protection.outlook.com (A) while asking recursive_nameserver1.parent. Error was: unable to reach nameserver on any valid IP' (delivery attempts: 0)> #SMTP#

hope you help this out. thanks.

[Robert Sherwin]

Was that the actual domain listed?  "domain.mail.protection.outlook.com", DNS name does not resolve from my end.

Usually the mail.protection.outlook.com are tailored for specific domains, ie. contoso-com.mail.protection.outlook.com

http://blogs.technet.com/b/eopfieldnotes/archive/2014/08/06/one-mx-to-rule-them-all.aspx

Helpful links outside of Cisco - pointing towards Microsoft/Office --- people report same in older posts:

https://community.office365.com/en-us/f/155/t/133928

More than likely, someone had bad addresses/domain based email (spam or not) going through by accident to the "domain.mail.protection.outlook.com" --- so, misconfigured DNS would not route, sit & then timeout/bounce...

-Robert

[CHARLES FRANCIS]

We are seeing something similar.  We cannot email any domain that appears to be hosted by Office 365

[Robert Sherwin]

Would suggest to open a support case/call with Microsoft then, and troubleshoot connection from your end to the delivery end --- the 5.0.0 errors would be indicating that issue would be recipient side.  

-Robert