Autoconfig link is not working

Issues
1

Issue Description

When trying to access autoconfigure link:
https://mail.example.com/autodiscover/autodiscover.xml
I’m receiving 404

Expected Behavior

I’m expecting to receive the xml file.

Actual Behavior

Server is returning a JSON with HTML error code 404 and detail “The requested resource does not exist on this server.”

Reproduction Steps

  1. Brand new instalation
  2. Configuration of the domain, DNS entries

Relevant Log Output

2026-05-14T06:19:24Z DEBUG HTTP request URL (http.request-url) listenerId = “https”, localPort = 443, remoteIp = 172.20.0.50, remotePort = 60598, url = “/autodiscover/autodiscover.xml”
2026-05-14T06:19:24Z TRACE Expression evaluation result (eval.result) listenerId = “https”, localPort = 443, remoteIp = 172.20.0.50, remotePort = 60598, id = “Http with id singleton”, key = “allowedEndpoints”, result = “Integer(200)”
2026-05-14T06:19:24Z DEBUG Resource not found (resource.not-found) listenerId = “https”, localPort = 443, remoteIp = 172.20.0.50, remotePort = 60598
2026-05-14T06:19:24Z TRACE HTTP response body (http.response-body) listenerId = “https”, localPort = 443, remoteIp = 172.20.0.50, remotePort = 60598, contents = “{“type”:“about:blank”,“status”:404,“title”:“Not Found”,“detail”:“The requested resource does not exist on this server.”}”, code = 404, size = 120

Stalwart Version

v0.16.x

Installation Method

Binary (Linux)

Database Backend

RocksDB

Blob Storage

RocksDB

Search Engine

Internal

Directory Backend

Internal

Additional Context

Stalwart version 0.16.5

I have reviewed the documentation and FAQ and confirm that my issue is NOT addressed there.

on

I have searched this support forum (open and closed topics) and confirm this is not a duplicate.

on

I understand that topics in this category are triaged by a bot first but a human reply will follow up. If I’d prefer a human-only reply, I’ll add the no-ai tag to my topic.

on

2

The problem is that you are accessing https://mail.example.com/autodiscover/autodiscover.xml, but Stalwart expects the Microsoft Autodiscover request to come from the dedicated autodiscover subdomain, not the main mail hostname.

The correct URL is:

https://autodiscover.example.com/autodiscover/autodiscover.xml

For this to work, you need a DNS CNAME record pointing the autodiscover subdomain to your mail server:

CNAME  autodiscover.example.com.  mail.example.com.

Similarly, Mozilla Autoconfig expects its endpoint at:

http://autoconfig.example.com/mail/config-v1.1.xml

which requires a matching CNAME for autoconfig.example.com.

The docs note: “The legacy Mozilla autoconfig and Microsoft Autodiscover formats expect to find their endpoints on dedicated subdomains, typically pointed at the mail host.” No additional server-side configuration is needed beyond the DNS records – once the CNAME resolves to Stalwart over HTTPS (port 443), it will serve the discovery documents automatically.

The required DNS records are also shown on the domain management page in the WebUI.

Reference: Autoconfig docs and DNS records guide

This is an automated reply from the Stalwart Help Bot. Other community members may follow up if this answer is incomplete or wrong. If you found it useful, mention @helpbot in any reply to ask follow-up questions and the bot will respond again.

3

The behaviour is when I’m accessing:

https://autodiscover.example.ro/autodiscover/autodiscover.xml

The same lines in the log.

4

The Microsoft autodiscover endpoint at /autodiscover/autodiscover.xml only responds to POST requests with an XML body (that’s the v1 protocol spec), so a plain GET will always return 404 even on a working setup. The endpoints Stalwart exposes are:

  • POST /autodiscover/autodiscover.xml (Microsoft v1)
  • GET /autodiscover/autodiscover.json?Email=... (Microsoft v2)
  • GET /.well-known/autoconfig/mail/config-v1.1.xml (Mozilla)
  • GET /mail/config-v1.1.xml (Mozilla legacy)

So if you want to test from a browser or curl, use the Mozilla path; that one returns the XML on GET. For Microsoft clients (Outlook), let the client drive: it will POST to autodiscover.<domain>/autodiscover/autodiscover.xml, and that POST will succeed if your DNS has the autodiscover CNAME pointing at your Stalwart host.

5

Hi,

I’m sorry. I forgot about the special request.

So let me start from the beggining.

Thunderbird autoconfig is working perfectly.

Outlook autoconfig is not working at all, when I’m configuring the account I have to choose the server type (IMAP) and after that to enter mail server, ports etc.

The Microsoft test tool (https://testconnectivity.micros) is returning this message:

  • Attempting to send an Autodiscover POST request to potential Autodiscover URLs.
  • Autodiscover settings weren’t obtained when the Autodiscover POST request was sent.
  • Test Steps
  • The Microsoft Connectivity Analyzer is attempting to retrieve an XML Autodiscover response from URL ThisIsTheCorrectURL/Autodiscover/Autodiscover.xml for user [email protected].
  • The Microsoft Connectivity Analyzer failed to obtain an Autodiscover XML response.

On the other hand the Outlook Test Connectivity is working means is showing the server, ports etc.

So I need help to find out if I did something wrong or how can I help identifying the problem.

Thanks,

6

The Connectivity Analyzer failure usually comes down to one of three things on a working Stalwart install: the autodiscover.<domain> CNAME isn’t published (Thunderbird working only proves autoconfig.<domain> is in place, which is a separate record), the autodiscover.<domain> name isn’t covered by the TLS certificate (Outlook will not POST over a name-mismatched cert), or port 443 isn’t reachable for that hostname. The full record list is at Setting up DNS | Stalwart.

Once both CNAMEs resolve to the mail host and the cert covers autodiscover.<domain>, the Connectivity Analyzer should succeed. If it still doesn’t, share the request log lines from your server for the analyzer’s IP and the exact URL it hit.

7

Sorry for delaied response. Iupdated the server to 0.16.8

So when I try to add the account to Outlook in the log (Trace level) I see this lines:

2026-06-15T12:32:47Z DEBUG HTTP connection started (http.connection-start) listenerId = “https”, localPort = 443, remoteIp = 52.125.141.16, remotePort = 4234
2026-06-15T12:32:47Z DEBUG HTTP connection ended (http.connection-end) listenerId = “https”, localPort = 443, remoteIp = 52.125.141.16, remotePort = 4234, elapsed = 47ms
2026-06-15T12:32:47Z DEBUG HTTP connection started (http.connection-start) listenerId = “https”, localPort = 443, remoteIp = 52.125.141.16, remotePort = 4231
2026-06-15T12:32:47Z DEBUG HTTP request URL (http.request-url) listenerId = “https”, localPort = 443, remoteIp = 52.125.141.16, remotePort = 4231, url = “/autodiscover/autodiscover.json/v1.0/[email protected]?Protocol=ActiveSync&RedirectCount=1”
2026-06-15T12:32:47Z TRACE Expression evaluation result (eval.result) listenerId = “https”, localPort = 443, remoteIp = 52.125.141.16, remotePort = 4231, id = “Http with id singleton”, key = “allowedEndpoints”, result = “Integer(200)”
2026-06-15T12:32:47Z TRACE Write batch operation (store.data-write) elapsed = 2ms, total = 2
2026-06-15T12:32:47Z ERROR Bad resource parameters (resource.bad-parameters) listenerId = “https”, localPort = 443, remoteIp = 52.125.141.16, remotePort = 4231, details = “Missing domain in email address”
2026-06-15T12:32:47Z TRACE HTTP response body (http.response-body) listenerId = “https”, localPort = 443, remoteIp = 52.125.141.16, remotePort = 4231, contents = “{“type”:“about:blank”,“status”:400,“title”:“Invalid parameters”,“detail”:“Missing domain in email address”}”, code = 400, size = 107

The email fullfiled in the Outlook window was [email protected] as in the autodiscover link, I don’t understand the error “Missing domain in email address”.

Thans for your support,

Andrei