A spurious invocation carries no action for a reader, so mailing it just
trains them to skip past the subject line -- which defeats the point of the
alert. Send mail only when the unit actually reports failure; spurious
triggers still leave their journald record, so they stay greppable and can
still feed a Graylog rule.
Verified both paths: a spurious trigger leaves /var/log/msmtp.log untouched
and logs alert_mail=skipped reason=spurious, while a genuinely failed unit
still composes mail with the FAILED subject.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Bastian de Byl
16145fb6bd