| | 1 | = Strict DMARC strategy = |
| | 2 | |
| | 3 | Yahoo is asking email providers to use strict alignment when evaluating DMARC policies for email messages claiming to be from Yahoo (see [wiki:dmarc-and-mailing-lists our general FAQ for more information]. |
| | 4 | |
| | 5 | This page describes our technical approach to addressing this problem. |
| | 6 | |
| | 7 | Our mailing list software relays ''all'' mail to dedicated email relay machines (see [wiki:bulk-mail-relay our bulk mail relay] page for details on how that system operates. |
| | 8 | |
| | 9 | Through our [wiki:puppet puppet configuration] (modules/mayfirst/manifests/postfix.pp), our bulk mail relay machines use [http://www.postfix.org/header_checks.5.html Postfix header checks] to replace the From: line from any email message that is from a yahoo account to a custom address. Here's the regular expression: |
| | 10 | |
| | 11 | {{{ |
| | 12 | /From: (.*<?.*@yahoo\.com(\.[a-z][a-z])?>?)/ REPLACE From: "$1 (Relayed)" <strict-dmarc@mayfirst.org> |
| | 13 | }}} |
| | 14 | |
| | 15 | The custom address has an auto-responder that refers people to our [wiki:dmarc-and-mailing-lists general FAQ] on this topic. |
