eml1.6 KB

EML — DSN Reporting Two Recipients With Different Outcomes

One multipart/report carrying two per-recipient blocks: a permanent 5.1.1 failure and a temporary 4.4.7 delay for the same original message. Bounce processors that read only the first block suppress a good address, or keep retrying a dead one.

Email parsing Conversion testing

Preview — first 47 lineseml

From: Mail Delivery Subsystem <MAILER-DAEMON@mx1.meridiansupply.example>
To: Maya Chen <maya@brightside.example>
Subject: Delivery Status Notification (failure and delay) SAMPLE
Date: Mon, 16 Feb 2026 07:46:00 -0800
Message-ID: <p7-dsn-multi@mx1.meridiansupply.example>
Auto-Submitted: auto-replied
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status; boundary="=_p7_dsn_p7-dsn-multi"

--=_p7_dsn_p7-dsn-multi
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit

This report covers two recipients of one message.

  sam@meridiansupply.example  delivery delayed, retrying until 20 Feb
  dana@nonexistent.example    permanent failure, no such user
--=_p7_dsn_p7-dsn-multi
Content-Type: message/delivery-status

Reporting-MTA: dns; mx1.meridiansupply.example
Arrival-Date: Mon, 16 Feb 2026 07:45:12 -0800

Final-Recipient: rfc822; dana@nonexistent.example
Action: failed
Status: 5.1.1
Remote-MTA: dns; mx.nonexistent.example
Diagnostic-Code: smtp; 550 5.1.1 SAMPLE - no such user

Final-Recipient: rfc822; sam@meridiansupply.example
Action: delayed
Status: 4.4.7
Will-Retry-Until: Fri, 20 Feb 2026 07:45:12 -0800
Diagnostic-Code: smtp; 451 4.4.7 SAMPLE - queued, will retry
--=_p7_dsn_p7-dsn-multi
Content-Type: text/rfc822-headers

From: Maya Chen <maya@brightside.example>
To: Sam Rivera <sam@meridiansupply.example>
Subject: Standing order for Q1 (SAMPLE)
Date: Mon, 16 Feb 2026 07:45:00 -0800
Message-ID: <p7-dsn-original@brightside.example>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
--=_p7_dsn_p7-dsn-multi--

Specifications

Wave: p7
Seed: 20260807
Report Type: delivery-status
Recipient Blocks: 2
Actions: failed + delayed
Statuses: 5.1.1 + 4.4.7
Line Endings: CRLF (RFC 5322)

Testing contract

Expected to pass

Scenario: Extract per-recipient outcomes from a DSN whose message/delivery-status part holds more than one recipient block.
Expected result: Two recipients are reported — dana@nonexistent.example as a permanent 5.1.1 failure and sam@meridiansupply.example as a retryable 4.4.7 delay.

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 — DSN Reporting Two Recipients With Different Outcomes” is a deterministic Novus Examples fixture for Email parsing, Conversion testing. 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: seed 20260807 · CRLF (RFC 5322). 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("p7-dsn-multi-recipient.eml", "rb"))
print(msg["subject"], msg["from"])