postday

I am now receiving a different mail delivery fail message after I speaking with the server:

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

 [email protected]
   host gmail-smtp-in.l.google.com [173.194.76.26]
   SMTP error from remote mail server after end of data:
   550-5.7.26 Your email has been blocked because the sender is unauthenticated.
   550-5.7.26 Gmail requires all senders to authenticate with either SPF or DKIM.
   550-5.7.26
   550-5.7.26  Authentication results:
   550-5.7.26  DKIM = did not pass
   550-5.7.26  SPF [post.day] with ip: [91.109.115.123] = did not pass
   550-5.7.26
   550-5.7.26  For instructions on setting up authentication, go to
   550 5.7.26  https://support.google.com/mail/answer/81126#authentication ffacd0b85a97d-37cd56ead3fsi3463367f8f.905 – gsmtp
Reporting-MTA: dns; lon16.onrocket.com

Action: failed
Final-Recipient: rfc822;[email protected]
Status: 5.0.0
Remote-MTA: dns; gmail-smtp-in.l.google.com
Diagnostic-Code: smtp; 550-5.7.26 Your email has been blocked because the sender is unauthenticated.
550-5.7.26 Gmail requires all senders to authenticate with either SPF or DKIM.
550-5.7.26
550-5.7.26  Authentication results:
550-5.7.26  DKIM = did not pass
550-5.7.26  SPF [post.day] with ip: [91.109.115.123] = did not pass
550-5.7.26
550-5.7.26  For instructions on setting up authentication, go to
550 5.7.26  https://support.google.com/mail/answer/81126#authentication ffacd0b85a97d-37cd56ead3fsi3463367f8f.905 – gsmtp