- Deleted a user's preferences, changed globals, purged cache, made sure defaults reflected global defaults.
- Changed global mail tags, sent mail to the user, verified it was dropped in accordinace with global settings.
- Changed user's settings to get the mail instead, verified mail was sent.
- Toggled user's Re / Vary settings, verified mail subject lines reflected user settings.
- Disabled `metamta.one-mail-per-recipient`, verified user "Email Format" panel vanished.
- Edited "Email Format" in single-mail-mode in global prefs as an administrator.
- Sent more mail, verified mail respected new global settings.