fix: Special envelope handling for LarkSuite accounts

Author: andris9

lib/email-client/imap-client.js

@@ -543,6 +543,7 @@ class IMAPClient extends BaseClient {
         // User might have disabled All Mail folder access and in that case we should treat it as a regular mailbox
         this.isGmail = imapClient.capabilities.has('X-GM-EXT-1') && listing.some(entry => entry.specialUse === '\\All');
         this.isOutlook = /\boffice365\.com$/i.test(imapClient.host); // || /The Microsoft Exchange IMAP4 service is ready/.test(imapClient.greeting);
+        this.isLarkSuite = /\blarksuite\.com$/i.test(imapClient.host);
 
         const accountPaths = [].concat(accountData.path || '*');
         if (!accountPaths.length) {

lib/email-client/imap/mailbox.js

@@ -23,6 +23,7 @@ const appendList = require('../../append-list');
 const { mimeHtml } = require('@postalsys/email-text-tools');
 const simpleParser = require('mailparser').simpleParser;
 const ical = require('ical.js');
+const addressparser = require('nodemailer/lib/addressparser');
 const { llmPreProcess } = require('../../llm-pre-process');
 
 const { getESClient } = require('../../document-store');
@@ -84,6 +85,8 @@ class Mailbox {
         this.isGmail = connection.isGmail;
         this.isAllMail = this.isGmail && this.listingEntry.specialUse === '\\All';
 
+        this.isLarkSuite = connection.isLarkSuite;
+
         this.selected = false;
         // does the mailbox open happen before or after initial syncing
         this.previouslyConnected = false;
@@ -1343,7 +1346,7 @@ class Mailbox {
             isDraft = true;
         }
 
-        // do not expose the \Recent flag as it is session specific
+        // Do not expose the \Recent flag as it is session specific
         if (messageData.flags && messageData.flags.has('\\Recent')) {
             messageData.flags.delete('\\Recent');
         }
@@ -1352,6 +1355,41 @@ class Mailbox {
             isDraft = true;
         }
 
+        let headers;
+
+        // This section is needed for Lark Mail as some address fields might be missing
+        // from the ENVELOPE section, so fall back to the header instead.
+        // Normally, these headers are not fetched from the server and only ENVELOPE is used
+        let parsedAddresses = {};
+        if (messageData.headers) {
+            headers = libmime.decodeHeaders(messageData.headers.toString().trim());
+            for (let key of ['from', 'to', 'cc', 'bcc']) {
+                if (headers[key]?.length) {
+                    try {
+                        const addressList = addressparser(headers[key])
+                            .filter(address => !!address.address)
+                            .map(address => {
+                                let name = address.name;
+                                try {
+                                    name = libmime.decodeWords(name);
+                                } catch (err) {
+                                    // ignore
+                                }
+                                return {
+                                    name,
+                                    address: address.address
+                                };
+                            });
+                        if (addressList?.length) {
+                            parsedAddresses[key] = addressList;
+                        }
+                    } catch (err) {
+                        // just ignore
+                    }
+                }
+            }
+        }
+
         const result = {
             id: packedUid,
             uid: messageData.uid,
@@ -1374,21 +1412,21 @@ class Mailbox {
 
             size: messageData.size || undefined,
             subject: envelope.subject || undefined,
-            from: envelope.from && envelope.from[0] ? envelope.from[0] : undefined,
+            from: envelope.from?.[0] ? envelope.from[0] : parsedAddresses.from?.[0] || undefined,
 
             replyTo: envelope.replyTo && envelope.replyTo.length ? envelope.replyTo : undefined,
             sender: extended && envelope.sender && envelope.sender[0] ? envelope.sender[0] : undefined,
 
-            to: envelope.to && envelope.to.length ? envelope.to : undefined,
-            cc: envelope.cc && envelope.cc.length ? envelope.cc : undefined,
+            to: envelope.to?.length ? envelope.to : parsedAddresses.to || undefined,
+            cc: envelope.cc?.length ? envelope.cc : parsedAddresses.cc || undefined,
 
             bcc: extended && envelope.bcc && envelope.bcc.length ? envelope.bcc : undefined,
 
             attachments: attachments && attachments.length ? attachments : undefined,
             messageId: (envelope.messageId && envelope.messageId.toString().trim()) || undefined,
             inReplyTo: envelope.inReplyTo || undefined,
 
-            headers: (extended && messageData.headers && libmime.decodeHeaders(messageData.headers.toString().trim())) || undefined,
+            headers: (extended && headers) || undefined,
             text: textId
                 ? {
                       id: textId,
@@ -2072,6 +2110,13 @@ class Mailbox {
 
             fetchHeaders.add('content-type');
 
+            if (this.isLarkSuite) {
+                // add address headers as a fallback to use if ENVELOPE does not include a specific address field (no idea why it happens)
+                fetchHeaders.add('from');
+                fetchHeaders.add('to');
+                fetchHeaders.add('cc');
+            }
+
             messageFetchOptions.fetchHeaders = Array.from(fetchHeaders);
         }
 
@@ -2904,6 +2949,20 @@ class Mailbox {
                 labels: true
             };
 
+            if (this.isLarkSuite) {
+                if (!fields.headers && fields.headers !== true) {
+                    fields.headers = [];
+                }
+                if (Array.isArray(fields.headers)) {
+                    // ensure that the response includes header fiels because Lark Mail ENVELOPE response is unreliable
+                    for (let key of ['from', 'to', 'cc']) {
+                        if (!fields.headers.includes(key)) {
+                            fields.headers.push(key);
+                        }
+                    }
+                }
+            }
+
             for await (let messageData of connectionClient.fetch(range, fields, opts)) {
                 if (!messageData || !messageData.uid) {
                     //TODO: support partial responses