Log rules and display rules
Mail Log has two kinds of rules that are easy to confuse but do very different things. Both are found in the options.
Log rules decide which mails are stored at all.
Display rules only decide which stored mails appear in the list.
Log rules: what is never stored in the first place
Log rules take effect before anything is written to the database. That keeps uninteresting bulk mail out of the log — noisy notifications from a particular service, for instance. What a log rule excludes never becomes an entry.
Two settings determine the behaviour:
| Mode | Exclude matches — matching mails are NOT logged. Include matches only — ONLY matching mails are logged, everything else is discarded. |
| Match | Whether a mail has to satisfy all rules (AND) or any of them (OR). |
Display rules: what is hidden in the list
Display rules take effect after storing. Matching entries are merely hidden in the list and on the dashboard — nothing is deleted. Change the rule and the entries reappear. Useful for tidying up an overloaded view without losing data.
How a rule is put together
Both rule types are built from the same parts. Every rule checks a field with an operator against a value:
| Field | Subject, body, recipient or sender. |
| Operator | contains, does not contain, equals, does not equal, starts with, ends with — for display rules additionally is empty / is not empty. |
| Value | The text to compare against. |
Examples
- Do not log cron job mails: log rule, mode exclude matches, field
sender, operator contains, value
cron@. - Log order mails only: log rule, mode include matches only, field
subject, operator contains, value
order. - Hide internal test mails: display rule, field recipient, operator
ends with, value
@internal.example.
The mode include matches only for log rules is sharp: everything that does not match is not logged. Use it deliberately and check afterwards that the mails you want still reach the log.
Applies to version 1.0.5.