[JMAP] Sorting issue: Oldest emails appear at the top instead of newest (ignores isAscending: false)

[bartfaizoli76]

Issue Description

I am using Bulwark Webmail (JMAP) as a client for Stalwart Mail Server. When opening heavily populated or migrated folders like Inbox or Sent, the oldest emails (from years ago) are displayed at the very top. It seems the JMAP Email/query is returning results based on insertion order (or an unindexed order) rather than the requested receivedAt date.

Expected Behavior

When a JMAP client requests Email/query with "sort": [{"property": "receivedAt", "isAscending": false}], the server should return the most recently received emails first.

Actual Behavior

The server returns the oldest emails first (e.g., from 2020), ignoring the descending sort order request for receivedAt.
Note: IMAP clients (like Roundcube) connected to the same server show the correct chronological order, indicating the data is intact but the JMAP search/sort index might be failing to sort correctly.

Reproduction Steps

Connect a JMAP client (like Bulwark Webmail) to Stalwart.

Navigate to a folder with a large history of emails (e.g., Inbox).

The client sends an Email/query requesting descending order.

Observe the returned email IDs in the response: the oldest emails are returned first.

Relevant Log Output

// REQUEST (Client)
"methodCalls": [
  [
    "Email/query",
    {
      "accountId": "b9",
      "filter": { "inMailbox": "a" },
      "sort": [
        {
          "property": "receivedAt",
          "isAscending": false
        }
      ],
      "limit": 50,
      "position": 0,
      "calculateTotal": true
    },
    "0"
  ]
]

// RESPONSE (Server snippet showing old emails returned at the top)
"list": [
  {
    "id": "huaaaabe",
    "receivedAt": "2024-07-20T14:41:03Z",
    "subject": "Fwd: Heti jelentés"
  },
  {
    "id": "miaaaacz",
    "receivedAt": "2024-07-20T13:52:46Z",
    "subject": "Tudatos vezetők klubja"
  },
  {
    "id": "ddeaaaajk",
    "receivedAt": "2020-09-29T07:51:08Z",
    "subject": "Vállalkozói Sikerklub"
  }
]

Stalwart Version

v0.15.x

Installation Method

Docker

Database Backend

RocksDB

Blob Storage

RocksDB

Search Engine

Internal

Directory Backend

Internal

Additional Context

Client software: Bulwark Webmail v1.4.12 (Next.js 16.1.6)

Proxy configuration: Nginx v1.26.3 handling SSL termination and CORS.

Troubleshooting done: I have already tried disabling "Conversation Grouping" in Bulwark Webmail settings, but the sorting remains incorrect for the Inbox and Sent folders.

IMAP works: The same backend serves IMAP correctly (tested with Roundcube), so this is strictly related to JMAP.

I acknowledge that:

• I have reviewed the documentation and FAQ and confirm that my issue is NOT addressed there.
• I have searched the Stalwart repository (both open and closed Discussions and Issues) and confirm this is not a duplicate.
• I have set the logging level to trace and included relevant log output if applicable.
• I agree to follow the project's Code of Conduct.