Email Thread Explorer
Select several .eml files to reconstruct a reply tree from message reference headers. Inspect each message's sender, recipient, date, body, quoted text and attachment name, type and size. A text/plain part takes priority; when it is absent, HTML is parsed only for visible text. HTML, images and links are never rendered or fetched, so tracking pixels are not requested. No mail is sent and no account is accessed.
Key features
- Reply tree from Message-ID, In-Reply-To and References with duplicate and missing-parent findings
- Folded RFC 5322 headers and a bounded RFC 2047 subject decoder
- Prefer text/plain in MIME multipart/alternative; extract text only from HTML fallback
- Separate lines beginning with '>' or HTML blockquote from the main body
- List attachment name, Content-Type and decoded byte count without opening content
How to use
- Load the two-message example or select several local .eml files.
- Review unreadable files, duplicate Message-IDs and other findings.
- Choose a message in the reply tree to inspect sender, recipient, date and ID.
- Read its text body, identified quoted text and attachment metadata.
- If exact MIME layout or attachment content matters, check the originals in a trusted mail client.
Use cases
- Reconstruct reply order from exported EML files
- Spot duplicate Message-IDs or references to missing messages
- Read HTML email text without loading remote images
- Review attachment names, types and sizes
Frequently asked questions
Does this send mail or sign in to an account?
No. It reads only local EML files you select in tab memory. There is no account connection, sending or server upload.
Can remote images or scripts in HTML run?
No. HTML is parsed offline into text while scripts, styles, frames and forms are discarded. Image URLs and link targets are never fetched; output is text, not rendered HTML.
Where does a reply go if Message-ID is duplicated?
When more than one message has the same ID, the ID is ambiguous and the reply is not assigned to either copy arbitrarily. A reference absent from the selected set is shown as a missing-parent finding and remains a root.
Does it perfectly separate replies and quoted text?
No. It separates plain-text lines beginning with '>' and HTML blockquote elements. Client-specific quoted CSS, forwarded messages and complex quoting styles are not recognized.
Which EML and encodings are supported?
The bounded subset handles basic RFC 5322 headers, selected RFC 2047 encoded words, MIME multipart, base64/quoted-printable/7bit/8bit, and UTF-8, ASCII, ISO-8859-1 or Windows-1252 text. S/MIME, PGP, RFC 2231 extended filenames, nested message/rfc822 attachments and universal mail-client fidelity are unsupported. Limits are 20 files, 750 KB each and 4 MB total.
Privacy
Selected EML bytes are read only in this browser tab's memory. They are not uploaded or automatically saved. Attachments are not downloaded or opened. Close the tab after reviewing sensitive mail on a shared device.
Comments & questions