eml339 B

EML Delivery — Bounce Mailbox Full

SAMPLE delivery/DSN-related .eml (bounce-mailbox-full) for mailbox parsers.

Preview, first 10 lineseml

From: Mailer-Daemon <mailer-daemon@mail.sample.example>
To: Alex SAMPLE <alex@brightside.example>
Subject: Undelivered Mail Returned to Sender
Date: Wed, 22 Jul 2026 10:10:00 -0400
Message-ID: <wi-bounce-full@mail.sample.example>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8

SAMPLE bounce: mailbox full (552 5.2.2).

Specifications

Role: delivery-variant
Wave: I

Testing contract

Expected to pass

Scenario: Exercise EML Delivery — Bounce Mailbox Full in its dsn workflow. SAMPLE delivery/DSN-related .eml (bounce-mailbox-full) for mailbox parsers.
Expected result: subject='Undelivered Mail Returned to Sender'; content type=text/plain; MIME leaf parts=1. Declared feature checks: role=delivery-variant.

What is a .eml file?

An EML file is a single email message stored in the RFC 822 / MIME format: plain-text headers (From, To, Subject, Date, Message-ID) followed by the body, which may be plain text, HTML, or a multipart structure with alternative bodies and file attachments encoded in base64.

How to use this file

Use an example EML to test email header parsing, MIME decoding, HTML-part handling, attachment extraction, and EML-to-other-format conversion.

How to use this file for testing

“EML Delivery — Bounce Mailbox Full” is a deterministic Novus Examples fixture for Email parsing. Standards-compliant RFC 822 messages (plain, multipart text+HTML, and with an attachment) plus an MBOX mailbox, for testing header parsing, MIME decoding, attachment extraction, and mailbox splitting.

Documented properties for this file: delivery-variant. Compare results against paired or grouped companions on this page when present (clean↔damaged, searchable↔scanned, or format twins) so scores stay reproducible across runs.

Download the file once, keep the path stable in CI or local scripts, and treat the spec table as the contract: dimensions, seeds, field lists, and roles are intentional. Corrupt or invalid samples are labelled as such, expect parsers to fail loudly rather than silently accept them.

Email fixtures use fixed dates, message IDs, and MIME boundaries so runs are reproducible, and every address is fictional. Test header parsing, MIME decoding, attachment extraction, and EML/MBOX conversion against the documented structure.

Code examples

from email import policy
from email.parser import BytesParser

msg = BytesParser(policy=policy.default).parse(open("bounce-mailbox-full.eml", "rb"))
print(msg["subject"], msg["from"])