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ActiveSync Test

The InteSys ActiveSync Test is a free tool for diagnosing Exchange ActiveSync (EAS) connectivity against Z-Push, Zimbra, and Microsoft Exchange servers. It validates authentication, discovers the negotiated EAS version, lists folders, and previews the inbox, contacts, and calendar. Access it at intesys.io/tools/activesync.

When to Use

Use this tool when mobile devices fail to sync properly, before performing an email migration, or to validate that a server is correctly exposing its ActiveSync endpoint.

What is ActiveSync?

Exchange ActiveSync (EAS) is a protocol developed by Microsoft for synchronizing email, calendar, contacts, and tasks on mobile devices. It is widely supported by:

  • iOS / iPhone / iPad — native support
  • Android — via apps like Nine, Outlook, or Samsung Email
  • Outlook — via Exchange or Microsoft 365 accounts
  • Servers: Microsoft Exchange, Z-Push (open source), and Zimbra (via Z-Push)

EAS uses WBXML (WAP Binary XML) over HTTPS on port 443, with HTTP Basic authentication headers.

What the Tool Checks

1. Discovery Handshake (OPTIONS)

Sends an HTTP OPTIONS request to /Microsoft-Server-ActiveSync and extracts:

  • Supported EAS versions (e.g., 2.5, 12.0, 12.1, 14.0, 14.1)
  • Available commands (Sync, FolderSync, GetItemEstimate, Ping, etc.)
  • Server headers (MS-Server-ActiveSync, X-Powered-By)

2. Provisioning (Provision)

Executes the provisioning policy handshake required by EAS 12.1+:

  • Requests a temporary policy key
  • Acknowledges the key to obtain a final valid key
  • Required for most subsequent commands

3. Folder Synchronization (FolderSync)

Lists all mailbox folders:

  • Inbox, Sent, Drafts, Trash
  • Calendar, Contacts, Tasks
  • User-created custom folders

4. Content Preview (Sync)

After successful authentication, the tool syncs and displays:

  • Recent messages — sender, subject, size, date
  • Contacts — name, email, phone, company
  • Calendar items — title, start date, end date, location

Ideal for Migrations

Use this tool to quickly validate that a new mailbox has been properly provisioned before configuring end users' mobile devices.

How to Use

  1. Navigate to intesys.io/tools/activesync
  2. Fill in the fields:
    • Server URL — e.g., mail.example.com or https://mail.example.com
    • Username — your full email address (e.g., [email protected])
    • Password — the mailbox password
  3. Click Run ActiveSync Test
  4. Wait a few seconds for the test to complete
  5. Review the results

Understanding Results

Overall Status

Status Meaning
Authenticated Credentials valid, EAS fully functional
Authenticated with warnings Authentication OK, but some features returned errors
Authentication failed Invalid credentials or user not enabled for EAS
Connection failed Server unreachable, invalid DNS, or port blocked

Returned Fields

  • Negotiated EAS version — The highest version supported by both client and server (ideal: 14.1)
  • Advertised versions — All versions the server accepts
  • Provision handshake — Indicates whether the device policy was accepted
  • Supported commands — List of EAS commands the server allows
  • Folders — Total number of syncable folders
  • Duration — Total test duration

Common Issues and Solutions

"Authentication failed" on Microsoft 365

Microsoft disabled Basic authentication for EAS on all Microsoft 365 tenants starting October 2022. Only modern OAuth 2.0 is supported, but traditional EAS with password authentication has been deprecated.

Solution: For Microsoft 365, use clients that support modern authentication (Outlook, Apple Mail iOS 14+) or the Microsoft Graph API instead of EAS.

"Connection failed"

  • Verify that the server URL is correct and reachable
  • Confirm that port 443 is not blocked by a firewall
  • Test whether the server responds at /Microsoft-Server-ActiveSync
  • Check the server's DNS A record

Invalid SSL certificate

EAS requires HTTPS with a valid certificate. Self-signed or expired certificates will cause failures. Use the SSL Checker tool to validate the certificate first.

EAS version too low

If the server negotiates EAS 2.5 or 12.0, some modern features (like search or recurring calendar items) may not work properly. Consider upgrading the server to support EAS 14.1.

Ping command not supported

The Ping command is essential for push notifications on mobile devices. If it is not in the list of supported commands, users will not receive new messages in real time — only via periodic polling.

Security and Privacy

  • No storage — Credentials are used only during the request and immediately discarded
  • No sensitive logs — No mailbox data is logged or stored
  • Server-to-server TLS — All traffic between the tool and the target server uses HTTPS
  • HTTPS required — The tool does not accept unencrypted connections

Learn More