`canonical_maps`

This parameter specifies optional address mapping lookup tables. The mapping is applied to both sender and recipient addresses, in both envelopes and in headers. This is typically used to clean up dirty addresses from legacy mail systems, or to replace login names by `Firstname.Lastname`. See Canonical Mapping for details.

By default, no canonical address mapping is done.

Sensible possible values:

- `dbm:/etc/postfix/canonical`
- `hash:/etc/postfix/canonical`
- `hash:/etc/postfix/canonical, nis:canonical`
- `hash:/etc/postfix/canonical, netinfo:/canonical`