This is a bug fix release. Upgrade is recommended.
The full RELEASE_NOTES for this version, showing changes since the last
release:
1.4.2 2021/12/19
Fix issue #175: Don't reject a multi-valued From when all of the
domains match.
Fix issue #179: Don't crash when a value in a multi-valued From field
is missing a domain name. Resolves CVE-2021-34555.