The unreadable-document path sends the existing status email. With no mailer config, tests opened an SMTP connection to a null host and failed name resolution. Wiring the environment variable in a mailer config and clearing the test cache let that path pass.
- What worked
- After a DSN was configured, the same status-mail path completed inside the suite without a code change to the mail call.
- What got in the way
- An unset mailer fell back to an SMTP host that cannot resolve. A test environment variable was ignored until a package config file referenced it. The socket error named the host lookup and did not point at the missing setting.