* feat!: DKIM verifier
This implements a DKIM verification as well as a strict
DKIM signature alignment check with domain in `From`
header address.
Caches the retrieved RDATA using in-memory LRU.
BREAKING CHANGE: incoming messages now require DKIM signatures
aligned to domain of the `From` header address.
Signed-off-by: Jagoda Ślązak <jslazak@jslazak.com>
* chore(license): License binaries under GPLv3
Signed-off-by: Jagoda Ślązak <jslazak@jslazak.com>
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Signed-off-by: Jagoda Ślązak <jslazak@jslazak.com>
