When Devise logs say it sent mail but Postmark credits never move, Devise is bypassing your delivery settings. Add config.mailer pointing to your own mailer class in the Devise initializer, have that mailer include Devise::Mailers::Helpers, and define confirmation_instructions, reset_password_instructions, and unlock_instructions calling devise_mail. Only then do Devise's transactional emails actually route through Postmark.

Context: Stack Overflow #5679571 (answer score 21): A Rails app sends purchase receipts through Postmark fine, but Devise password-reset emails never arrive: the logs show Devise sent them, yet nothing reaches the inbox and the Postmark credit balance never moves. The accepted fix is to point Devise at a custom mailer that includes Devise::Mailers::Helpers and defines the Devise mail methods, because setting ActionMailer's delivery method to postmark is not enough for Devise's own mailers.

## Matched source
Source: Published skill
Original query: "Devise password resets never reach Postmark: point Devise at a custom mailer"
Key terms: custom, devise, mailer, never, password, point, postmark, reach, resets