Strict parseaddr returns '' for common RFC-invalid From values that the
old regex resolved: an unquoted address as display name
(john@example.com <john@example.com>), an unquoted comma (Doe, John
<j@example.com>), or a@x.test <b@y.test>. Allowlisted senders using such
clients were silently dropped, and under open access every one of them
shared an empty chat_id. Fall back to the bracketed address only for the
unambiguous shape (no quotes, exactly one <...> pair), so the quoted
display-name spoof still resolves to the attacker. _parse_fetched_message
now drops messages whose From yields no address instead of dispatching
an empty identity.
The dmarc header.from alignment check read header.from from props merged
across all clauses, so a later dkim clause's header.from could override
the dmarc clause's value. Read it from the dmarc clause only, and pin the
misaligned dmarc=pass rejection in the existing dmarc test (previously
no test covered it). Also drop a redundant _domain_of ternary, trim the
_extract_email_address docstring and a duplicate test assertion.
2d44f5512b