Changes to MAIL-FROM Authentication in ARIN’s IRR

Posted: Fri, 07 October 2011

Aside from the improvements made in the IRR for authentication and notification, rolled out 29 September, there has been one change that has affected a number of users. 

To add the new functionality, ARIN took third party IRR software and integrated it within ARIN operations. The software that had the improved authentication system had explicitly disabled any MAIL-FROM authentication. ARIN inserted simple MAIL-FROM authentication, but regular expressions that were in the previous system are no longer supported. The “from” header which is generated by your Mail User Agent is used in matching your email address within the auth field of the mntner object. The two (from header and mail address) must match exactly. 

ARIN realizes that this is inconvenient for those who have regular expressions for their email address within the maintainer MAIL-FROM values. Please reference Section 2.5 of the ARIN Routing Registry Documentation for more information on the authentication methods, including steps for upgrading your existing mntner object with MAIL-FROM to either MD5 or PGP.

For assistance, please contact ARIN Registration Services at


Mark Kosters
Chief Technology Officer
American Registry for Internet Numbers (ARIN)