Do not treat non-failed DSNs as NDNs

CHANGELOG.md

@@ -7,6 +7,7 @@
 
 ### Fixes
 - don't squash text parts of NDN into attachments #3497
+- do not treat non-failed DSNs as NDNs #3506
 
 
 ## 1.89.0

src/message.rs

@@ -19,7 +19,7 @@ use crate::download::DownloadState;
 use crate::ephemeral::{start_ephemeral_timers_msgids, Timer as EphemeralTimer};
 use crate::events::EventType;
 use crate::imap::markseen_on_imap_table;
-use crate::mimeparser::{parse_message_id, FailureReport, SystemMessage};
+use crate::mimeparser::{parse_message_id, DeliveryReport, SystemMessage};
 use crate::param::{Param, Params};
 use crate::pgp::split_armored_data;
 use crate::scheduler::InterruptInfo;
@@ -1532,7 +1532,7 @@ pub async fn handle_mdn(
 /// Where appropriate, also adds an info message telling the user which of the recipients of a group message failed.
 pub(crate) async fn handle_ndn(
     context: &Context,
-    failed: &FailureReport,
+    failed: &DeliveryReport,
     error: Option<String>,
 ) -> Result<()> {
     if failed.rfc724_mid.is_empty() {
@@ -1588,7 +1588,7 @@ pub(crate) async fn handle_ndn(
 
 async fn ndn_maybe_add_info_msg(
     context: &Context,
-    failed: &FailureReport,
+    failed: &DeliveryReport,
     chat_id: ChatId,
     chat_type: Chattype,
 ) -> Result<()> {

src/mimeparser.rs

@@ -73,7 +73,7 @@ pub struct MimeMessage {
     pub(crate) user_avatar: Option<AvatarAction>,
     pub(crate) group_avatar: Option<AvatarAction>,
     pub(crate) mdn_reports: Vec<Report>,
-    pub(crate) failure_report: Option<FailureReport>,
+    pub(crate) delivery_report: Option<DeliveryReport>,
 
     /// Standard USENET signature, if any.
     pub(crate) footer: Option<String>,
@@ -332,7 +332,7 @@ impl MimeMessage {
             webxdc_status_update: None,
             user_avatar: None,
             group_avatar: None,
-            failure_report: None,
+            delivery_report: None,
             footer: None,
             is_mime_modified: false,
             decoded_data: Vec::new(),
@@ -535,7 +535,7 @@ impl MimeMessage {
         self.parse_system_message_headers(context);
         self.parse_avatar_headers(context).await;
         self.parse_videochat_headers();
-        if self.failure_report.is_none() {
+        if self.delivery_report.is_none() {
             self.squash_attachment_parts();
         }
 
@@ -869,7 +869,7 @@ impl MimeMessage {
                         // Some providers, e.g. Tiscali, forget to set the report-type. So, if it's None, assume that it might be delivery-status
                         Some("delivery-status") | None => {
                             if let Some(report) = self.process_delivery_status(context, mail)? {
-                                self.failure_report = Some(report);
+                                self.delivery_report = Some(report);
                             }
 
                             // Add all parts (we need another part, preferably text/plain, to show as an error message)
@@ -1280,9 +1280,46 @@ impl MimeMessage {
         &self,
         context: &Context,
         report: &mailparse::ParsedMail<'_>,
-    ) -> Result<Option<FailureReport>> {
+    ) -> Result<Option<DeliveryReport>> {
+        // Assume failure.
+        let mut failure = true;
+
+        if let Some(status_part) = report.subparts.get(1) {
+            // RFC 3464 defines `message/delivery-status`
+            // RFC 6533 defines `message/global-delivery-status`
+            if status_part.ctype.mimetype != "message/delivery-status"
+                && status_part.ctype.mimetype != "message/global-delivery-status"
+            {
+                warn!(context, "Second part of Delivery Status Notification is not message/delivery-status or message/global-delivery-status, ignoring");
+                return Ok(None);
+            }
+
+            let status_body = status_part.get_body_raw()?;
+
+            // Skip per-message fields.
+            let (_, sz) = mailparse::parse_headers(&status_body)?;
+
+            // Parse first set of per-recipient fields
+            if let Some(status_body) = status_body.get(sz..) {
+                let (status_fields, _) = mailparse::parse_headers(status_body)?;
+                if let Some(action) = status_fields.get_first_value("action") {
+                    if action != "failed" {
+                        info!(context, "DSN with {:?} action", action);
+                        failure = false;
+                    }
+                } else {
+                    warn!(context, "DSN without action");
+                }
+            } else {
+                warn!(context, "DSN without per-recipient fields");
+            }
+        } else {
+            // No message/delivery-status part.
+            return Ok(None);
+        }
+
         // parse as mailheaders
-        if let Some(original_msg) = report.subparts.iter().find(|p| {
+        if let Some(original_msg) = report.subparts.get(2).filter(|p| {
             p.ctype.mimetype.contains("rfc822")
                 || p.ctype.mimetype == "message/global"
                 || p.ctype.mimetype == "message/global-headers"
@@ -1303,9 +1340,10 @@ impl MimeMessage {
                     None // We do not know which recipient failed
                 };
 
-                return Ok(Some(FailureReport {
+                return Ok(Some(DeliveryReport {
                     rfc724_mid: original_message_id,
                     failed_recipient: to.map(|s| s.addr),
+                    failure,
                 }));
             }
 
@@ -1386,7 +1424,7 @@ impl MimeMessage {
         } else {
             false
         };
-        if maybe_ndn && self.failure_report.is_none() {
+        if maybe_ndn && self.delivery_report.is_none() {
             static RE: Lazy<regex::Regex> =
                 Lazy::new(|| regex::Regex::new(r"Message-ID:(.*)").unwrap());
             for captures in self
@@ -1400,9 +1438,10 @@ impl MimeMessage {
                     if let Ok(Some(_)) =
                         message::rfc724_mid_exists(context, &original_message_id).await
                     {
-                        self.failure_report = Some(FailureReport {
+                        self.delivery_report = Some(DeliveryReport {
                             rfc724_mid: original_message_id,
                             failed_recipient: None,
+                            failure: true,
                         })
                     }
                 }
@@ -1440,13 +1479,15 @@ impl MimeMessage {
             }
         }
 
-        if let Some(failure_report) = &self.failure_report {
+        if let Some(delivery_report) = &self.delivery_report {
-            let error = parts
+            if delivery_report.failure {
-                .iter()
+                let error = parts
-                .find(|p| p.typ == Viewtype::Text)
+                    .iter()
-                .map(|p| p.msg.clone());
+                    .find(|p| p.typ == Viewtype::Text)
-            if let Err(e) = message::handle_ndn(context, failure_report, error).await {
+                    .map(|p| p.msg.clone());
-                warn!(context, "Could not handle ndn: {}", e);
+                if let Err(e) = message::handle_ndn(context, delivery_report, error).await {
+                    warn!(context, "Could not handle ndn: {}", e);
+                }
             }
         }
     }
@@ -1526,6 +1567,7 @@ async fn update_gossip_peerstates(
     Ok(gossiped_addr)
 }
 
+/// Message Disposition Notification (RFC 8098)
 #[derive(Debug)]
 pub(crate) struct Report {
     /// Original-Message-ID header
@@ -1537,10 +1579,12 @@ pub(crate) struct Report {
     additional_message_ids: Vec<String>,
 }
 
+/// Delivery Status Notification (RFC 3464, RFC 6533)
 #[derive(Debug)]
-pub(crate) struct FailureReport {
+pub(crate) struct DeliveryReport {
     pub rfc724_mid: String,
     pub failed_recipient: Option<String>,
+    pub failure: bool,
 }
 
 #[allow(clippy::indexing_slicing)]

src/receive_imf.rs

@@ -497,9 +497,9 @@ async fn add_parts(
             ChatIdBlocked::lookup_by_contact(context, from_id).await?
         };
 
-        if chat_id.is_none() && mime_parser.failure_report.is_some() {
+        if chat_id.is_none() && mime_parser.delivery_report.is_some() {
             chat_id = Some(DC_CHAT_ID_TRASH);
-            info!(context, "Message belongs to an NDN (TRASH)",);
+            info!(context, "Message is a DSN (TRASH)",);
         }
 
         if chat_id.is_none() {
@@ -2749,6 +2749,19 @@ mod tests {
         .await;
     }
 
+    /// Test that DSN is not treated as NDN if Action: is not "failed"
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn test_parse_dsn_relayed() {
+        test_parse_ndn(
+            "anon_1@posteo.de",
+            "anon_2@gmx.at",
+            "8b7b1a9d0c8cc588c7bcac47f5687634@posteo.de",
+            include_bytes!("../test-data/message/dsn_relayed.eml"),
+            None,
+        )
+        .await;
+    }
+
     // ndn = Non Delivery Notification
     async fn test_parse_ndn(
         self_addr: &str,
@@ -2798,7 +2811,14 @@ mod tests {
         receive_imf(&t, raw_ndn, false).await.unwrap();
         let msg = Message::load_from_db(&t, msg_id).await.unwrap();
 
-        assert_eq!(msg.state, MessageState::OutFailed);
+        assert_eq!(
+            msg.state,
+            if error_msg.is_some() {
+                MessageState::OutFailed
+            } else {
+                MessageState::OutDelivered
+            }
+        );
 
         assert_eq!(msg.error(), error_msg.map(|error| error.to_string()));
     }

test-data/message/dsn_relayed.eml

@@ -0,0 +1,109 @@
+Return-Path: <>
+Delivered-To: anon_1@posteo.de
+Received: from proxy02.posteo.name ([127.0.0.1])
+	by dovecot16.posteo.name (Dovecot) with LMTP id 4LJTJKBpxGClSAAAchYRkQ
+	for <anon_1@posteo.de>; Sat, 12 Jun 2021 10:42:09 +0200
+Received: from proxy02.posteo.de ([127.0.0.1])
+	by proxy02.posteo.name (Dovecot) with LMTP id 0NENMHNXxGDI4AIAGFAyLg
+	; Sat, 12 Jun 2021 10:42:09 +0200
+Received: from mailin02.posteo.de (unknown [10.0.0.62])
+	by proxy02.posteo.de (Postfix) with ESMTPS id 4G2B686dbVz11xc
+	for <anon_1@posteo.de>; Sat, 12 Jun 2021 10:42:08 +0200 (CEST)
+Received: from mx01.posteo.de (mailin02.posteo.de [127.0.0.1])
+	by mailin02.posteo.de (Postfix) with ESMTPS id AC2472152F
+	for <anon_1@posteo.de>; Sat, 12 Jun 2021 10:42:08 +0200 (CEST)
+X-Virus-Scanned: amavisd-new at posteo.de
+X-Spam-Flag: NO
+X-Spam-Score: -1
+X-Spam-Level: 
+X-Spam-Status: No, score=-1 tagged_above=-1000 required=7
+	tests=[ALL_TRUSTED=-1] autolearn=disabled
+X-Posteo-Antispam-Signature: v=1; e=base64; a=aes-256-gcm; d=7/8PYiypR3F6lmk8rQGNxZgmuPRJI9wU2IwnCWX1fg/nFdbPrDu9pCFSVsnrK1SjAWJJ9HtJVYECbeMxMhq9tOMxZf1nSN2cM/XXzeH6ELaaQfOWfQbBff3ZIe+rix/CF1uWX164
+Authentication-Results: posteo.de; dmarc=none (p=none dis=none) header.from=mout02.posteo.de
+X-Posteo-TLS-Received-Status: TLSv1.3
+Received: from mout02.posteo.de (mout02.posteo.de [185.67.36.66])
+	by mx01.posteo.de (Postfix) with ESMTPS id 4G2B676wGBz10Wt
+	for <anon_1@posteo.at>; Sat, 12 Jun 2021 10:42:07 +0200 (CEST)
+Received: by mout02.posteo.de (Postfix)
+	id A9F481A0089; Sat, 12 Jun 2021 10:42:07 +0200 (CEST)
+Date: Sat, 12 Jun 2021 10:42:07 +0200 (CEST)
+From: MAILER-DAEMON@mout02.posteo.de (Mail Delivery System)
+Subject: Successful Mail Delivery Report
+To: anon_1@posteo.at
+Auto-Submitted: auto-replied
+MIME-Version: 1.0
+Content-Type: multipart/report; report-type=delivery-status;
+	boundary="56E6D1A007F.1623487327/mout02.posteo.de"
+Content-Transfer-Encoding: 7bit
+Message-Id: <20210612084207.A9F481A0089@mout02.posteo.de>
+
+This is a MIME-encapsulated message.
+
+--56E6D1A007F.1623487327/mout02.posteo.de
+Content-Description: Notification
+Content-Type: text/plain; charset=us-ascii
+
+This is the mail system at host mout02.posteo.de.
+
+Your message was successfully delivered to the destination(s)
+listed below. If the message was delivered to mailbox you will
+receive no further notifications. Otherwise you may still receive
+notifications of mail delivery errors from other systems.
+
+                   The mail system
+
+<anon_2@gmx.at>: delivery via mx00.emig.gmx.net[212.227.15.9]:25: 250
+    Requested mail action okay, completed: id=1M9ohD-1lvXys2NFd-005r3O
+
+--56E6D1A007F.1623487327/mout02.posteo.de
+Content-Description: Delivery report
+Content-Type: message/delivery-status
+
+Reporting-MTA: dns; mout02.posteo.de
+X-Postfix-Queue-ID: 56E6D1A007F
+X-Postfix-Sender: rfc822; anon_1@posteo.at
+Arrival-Date: Sat, 12 Jun 2021 10:42:07 +0200 (CEST)
+
+Final-Recipient: rfc822; anon_2@gmx.at
+Original-Recipient: rfc822;anon_2@gmx.at
+Action: relayed
+Status: 2.0.0
+Remote-MTA: dns; mx00.emig.gmx.net
+Diagnostic-Code: smtp; 250 Requested mail action okay, completed:
+    id=1M9ohD-1lvXys2NFd-005r3O
+
+--56E6D1A007F.1623487327/mout02.posteo.de
+Content-Description: Message Headers
+Content-Type: text/rfc822-headers
+
+Return-Path: <anon_1@posteo.at>
+Received: from mout02.posteo.de (unknown [10.0.0.66])
+	by mout02.posteo.de (Postfix) with ESMTPS id 56E6D1A007F
+	for <anon_2@gmx.at>; Sat, 12 Jun 2021 10:42:07 +0200 (CEST)
+Received: from submission-encrypt01.posteo.de (unknown [10.0.0.75])
+	by mout02.posteo.de (Postfix) with ESMTPS id 1C39E2400FD
+	for <anon_2@gmx.at>; Sat, 12 Jun 2021 10:42:07 +0200 (CEST)
+DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.at; s=2017;
+	t=1623487327; bh=+ZIKEoFCh8N5xYBj6tMbfqiyHmay76uM4H4bfme6VyU=;
+	h=Date:From:To:Subject:From;
+	b=QK6HwDU2YEzzTgHN2PRT2lPaf5uwC7ZJ1Y0QMSUrEyvJxwPj6+z6OoEqRDcgQcGVo
+	 biAO2aKyBX+YCFwM5a6CaJotv8DaL+hn/XLk3RKqxGKTu5cBLQXJc0gjfRMel7LnBg
+	 i0UxTeOqoTw2anWTonH2GnseUPtVAhi23UICVD6gC6DchuNYF/YloMltns5HMGthQh
+	 z279J05txneSKgpbU/R3fN2v5ACEve7X6GoxM0hDZRNmAur0HAxAREc9xIaHwQ3zXM
+	 dEGFyO53s+UzLlOFnY4vhGVI3AiyOZUProq6vX40g9e4TkrIJMGd1pyKG4NdajauuY
+	 KTIwbUiR5Y2Xw==
+Received: from customer (localhost [127.0.0.1])
+	by submission (posteo.de) with ESMTPSA id 4G2B665xBPz6tmH
+	for <anon_2@gmx.at>; Sat, 12 Jun 2021 10:42:06 +0200 (CEST)
+MIME-Version: 1.0
+Content-Type: multipart/alternative;
+ boundary="=_d0190a7dc3b70a1dcf12785779aad292"
+Date: Sat, 12 Jun 2021 08:42:06 +0000
+From: Anon_1 <anon_1@posteo.at>
+To: Anon_2 <anon_2@gmx.at>
+Subject: Hallo
+Message-ID: <8b7b1a9d0c8cc588c7bcac47f5687634@posteo.de>
+Posteo-User: anon_1@posteo.de
+Posteo-Dkim: ok
+
+--56E6D1A007F.1623487327/mout02.posteo.de--