I have been asked many times: is it possible to connect an email client other than Outlook to an Exchange server? The short answer is “yes”, but it is a roundabout process.
The easiest method is to connect a third-party email client that communicates IMAP to Outlook Web Access, through a proxy program, DavMail, which is a free and open source application. DavMail was written by Mickaël Guessant, and is available for several platforms (Windows, Mac, Linux). It allows you to access not only mail folders, but also directories and calendars, for example through Thunderbird with Apple’s Lightning or iCal extension. The main requirement is that Outlook Web Access is configured and running.
DavMail can be installed on multiple computers and used on each of them as a local proxy (eg many clients connecting from various external or private networks). But it can also be installed on a single machine (even the Exchange server) and used as a proxy connection for all your clients as long as that machine has clear access to OWA. Keep in mind that communications between the client and the proxy are not encrypted by default, so you must either encrypt the communications or make sure the network is secure.
Once you have installed DavMail, the most crucial part of the installation process is to configure the mail gateway, under the “Main” tab of the program in its settings window. This is the URL of your organization’s OWA page (usually http: // server / owa).
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You should also check the port assignments DavMail uses to accept incoming connections from your email clients. By default, these are set to values that should not conflict with existing applications or the defaults used by non-proxy versions of the same protocols. Example: the default IMAP port is 143; DavMail’s local proxy port for IMAP is 1143.
The next task is to configure the client. This process varies from client to client, but you generally need to make sure that:
- The client always points to the proxy, not to the remote server. If the proxy is running on the same machine, the name of the IMAP server is usually just local host.
- The username must be transmitted correctly. Depending on how you configured OWA, this is either in the format [email protected] Where domain user. DavMail cannot infer which domain name is appropriate by context; you must pass it on explicitly.
- The outgoing SMTP server must also be set to local host (the default port for DavMail is 1025) and must use the same username (in the [email protected] format) and the password you use for your OWA account.
- Provide exactly the correct Base DN for your searches. This will vary depending on your setup; I found that the supply or = people was sufficient for searches to work properly for the Exchange server I was using. Again, the server specified on the client should be local host, and the port must be the proxy LDAP port (by default, port 1389).
- Use the CalDAV protocol to access calendars with the following URL: http: // localhost: 1080 / users /[email protected]/calendar,or [email protected] is your username and domain name as used above. When prompted for credentials, use the usual [email protected]/password combination. The authors of DavMail recommend enabling calendar caching (if supported) to avoid long load times.
A remarkable amount of two-way synchronization is supported through DavMail. If you drag and drop a message from your local folders to a folder on the OWA server, for example, the message will be copied to the correct folder on the remote server.
The DavMail site includes fairly detailed walkthroughs for setting up the program and adding integration for calendar and other functions. Unfortunately, while the text of the walkthroughs is in English, the screenshots of most of the applications are in French. Thunderbird’s walkthrough isn’t much use either, as they use a much older version than the current one for their demonstration.
ABOUT THE AUTHOR: Serdar Yegulalp has been writing about computers and information technology for over 15 years for various publications including InformationWeek and Windows Magazine.