Summary: D19940 removed this file entirely, which has led to at least one user who was unsure how to proceed now that `cluster.mailers` is required for outbound mail: https://discourse.phabricator-community.org/t/invalid-argument-supplied-for-foreach-phabricatormetamtamail-php/2287 This isn't //always// a setup issue for installs that don't care about sending mail, but this at least this gives a sporting chance to users who don't follow the changelogs. Also, I'm not sure if there's a way to use `pht()` to generate links; right now the phurl is just in plain text. Test Plan: Removed `cluster.mailers` config; observed expected setup issue. Reviewers: epriestley Reviewed By: epriestley Subscribers: Korvin Differential Revision: https://secure.phabricator.com/D19964