# Postal Mime v3.0.0

- Product: Postal Mime (https://whatsnew.fyi/product/postal-mime)
- Vendor: Postal Systems
- Date: 2026-08-11
- Version: v3.0.0
- Original notes: https://github.com/postalsys/postal-mime/releases/tag/v3.0.0
- Permalink: https://whatsnew.fyi/product/postal-mime/releases/v3.0.0

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **changed** — header values in headers[].value keep the whitespace that folding introduced instead of having every whitespace run collapsed to a single space
- **changed** — single value headers such as subject and from resolve to the first occurrence of a duplicated header rather than the last
- **changed** — to, cc, bcc and replyTo are returned in document order rather than reversed
- **fixed** — resolve non-WHATWG charset labels instead of falling back to windows-1252
- **fixed** — unfold headers per RFC 5322 and resolve duplicated headers first-wins

##### [3.0.0](https://github.com/postalsys/postal-mime/compare/v2.7.6...v3.0.0) (2026-08-11)


###### ⚠ BREAKING CHANGES

* header values in `headers[].value` keep the whitespace that folding introduced instead of having every whitespace run collapsed to a single space, single value headers such as `subject` and `from` resolve to the first occurrence of a duplicated header rather than the last, and `to`, `cc`, `bcc` and `replyTo` are returned in document order rather than reversed.

###### Bug Fixes

* resolve non-WHATWG charset labels instead of falling back to windows-1252 ([6378618](https://github.com/postalsys/postal-mime/commit/6378618ac3faefd8fd96a44eb5f9a8bbe010e5b7)), closes [#94](https://github.com/postalsys/postal-mime/issues/94)
* unfold headers per RFC 5322 and resolve duplicated headers first-wins ([7b0ca9d](https://github.com/postalsys/postal-mime/commit/7b0ca9d5bcf1a31ce4f0fa230e552564a9789458))