1. Create a detailed description of the issue
You should include a specific description of the issue that users are reporting. This should include the following:
- The kind of connections that are failing in the environment, such as Outlook, Outlook Web App (OWA), or Exchange Web Services (EWS).
- Whether this issue is occurring intermittently or consistently
- Detailed repro steps
2. Does the issue occur in a specific office or network segment or on a specific Exchange mailbox server?
If just a subset of users is affected, it's important to note (if known) what the common factor may be. It might be a specific office, network segment, or users on a specific Exchange mailbox server.
3. How long has this issue been occurring?
Provide the length of time this issue has been experienced or the date when it was first noticed.
4. Is there a WAN accelerator in the environment?
Provide the manufacturer and model of the WAN accelerator and info about how long it has been production. Provide any recent changes or updates.
For more information about WAN accelerators, see 2690045: Using WAN Optimization Controller or Traffic/Inspection devices with Office 365.
5. List of affected users.
It will be helpful to have at least five users who are experiencing this issue.
6. Diagnostic information:
The Customer On Demand Diagnostics (CODD) tool is a Windows client application that's used to address access issues that members of your organization might experience when they try to use Office 365 Dedicated services.
This tool tests the following:
- Client system connectivity with the DNS server
- Ability of a client system to access the Internet
- Ability of the client to communicate with Exchange Online Dedicated client access servers
The output can be used to troubleshoot problems, including the following:
- Outlook Web App (OWA) main page fails to load
- Unable to interact with the Client Access server that provides OWA access
- Mail transport (SMTP-related) issues
- Outlook client connectivity failures
To run the tool, follow these steps:
If the CODD tool can't be used, follow these steps:
Nslookup -q=all mail.contoso.com
Article ID: 2451127 - Last Review: Dec 29, 2015 - Revision: 1