Description

When composing in rich-text/HTML mode, the auto-generated text/plain part of the multipart/alternative email has all line breaks stripped. Block boundaries (<p>, <div>, <br>) are not converted to newlines, so the plain-text alternative collapses into a single run-on line. Clients preferring the text part show unreadable output.

Steps to Reproduce

1. In rich-text mode, compose a body with multiple lines and/or a blank line:

   Line 1.
   Line 2.

   Paragraph 2.

2. Send, then inspect the raw source of the received message.

Expected Behavior

The text/plain part preserves line structure (Line 1. / Line 2. / blank / Paragraph 2. on separate lines).

Actual Behavior

Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit

Line 1.Line 2.Paragraph 2.

No format=flowed present, so this is not an RFC 3676 reflow artifact—the newlines are genuinely absent from the generated part.

Disabling rich-text/HTML mode produces correct line breaks, so the bug seems to be about the HTML→text derivation.

Bulwark Version

1.7.3-31-g798a334 (main)

Stalwart Mail Server Version

0.16.8

Browser

No response

Operating System

None

Screenshots / Screen Recording

No response

Relevant Logs or Error Output

Additional Context

Node v24.16.0.