Your message wasn't delivered because of security policies. Microsoft Exchange will not try to redeliver this message for you. Please provide the following diagnostic text to your system administrator.
The following organization rejected your message: mx.google.com.
Sent by Microsoft Exchange Server 2007
Diagnostic information for administrators:
Generating server: SERVER.[xxxx].local
mx.google.com #550-5.7.1 [2601:[xxxx]:c05c] Our system has detected that 550-5.7.1 this message does not meet IPv6 sending guidelines regarding PTR 550-5.7.1 records and authentication. Please review 550-5.7.1 https://support.google.com/mail/?p=ipv6_authentication_error for more 550 5.7.1 information. x75si3472751ioi.11 - gsmtp ##
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