#23 DavMail suddenly stopped working: 503 Service Unavailable

[Volkert]

I honestly don't understand it.

DavMail was working fine for months, with a Hosted Exchange service that is provided by a third party. Earlier this week, they had some quota issues and fixed something, DavMail has failed to work with this service ever since. Our Hosted Exchange provider keeps insisting that they haven't changed anything to the Exchange 2007 Server itself. No updates, patches, upgrades, or anything (although they did apply a patch or update a few months back, but the problem started occurring only a few days ago).

After some long searching, I found that in the class ExchangeSession, the string "/exchange/" is hardcoded as a prefix to the email address in the string variable mailPath (see line 561 at http://davmail.sourceforge.net/xref/davmail/exchange/ExchangeSession.html )

This results in a "503 Service Unavailable" error. Apparently, the URL "https://hostedExchangeServer/owa/email@domain" works fine (after showing a login form), but "https://hostedExchangeServer/exchange/email@domain" shows a 503 error (after showing the same login form).

So, I changed line 561 to prepend "/owa/" instead of "/exchange/" to mailPath. Alas, this resulted in a "501 Not Implemented" error.

I'm at a loss right now.

I suspect this is a bug, since I believe that hardcoding the string "/exchange/" as a prefix in case of Exchange 2007 environments is not correct. This is also what our provider told us: it's supposed to be "/owa/". "/exchange/" is for downwards compatibility with 2003 clients, and requires different login names. They would really like me to use "/owa/" instead.

Oh, and it doesn't matter whether I specify "https://hostedExchangeServer/owa/", "https://hostedExchangeServer/exchange/", just "https://hostedExchangeServer/", or any of those without a trailing "/" as value for "davmail.url" in davmail.properties. It doesn't matter, since DavMail is always redirected automatically by the Hosted Exchange service, as far as I can see in the logs. I've tried most of these combinations, and there was no difference.

Please, can anyone help me? We really need DavMail to work. Not just for SMTP and IMAP access, but also for CalDAV access. :(

Thank you.

[Mickael Guessant]

The /exchange path is hardcoded for Exchange 2007 because it's always the webdav path on Exchange 2007.

However, Webdav is not always available on Exchange 2007. You can check this by trying to access /exchange/mail@company.com/ in a web browser after authenticating to OWA => you should get a 302 redirect to /owa.

If you get any other error, this is definitely a server side issue.

[Volkert]

Thanks for your response. So if I understand correctly, DavMail will simply not work with Exchange 2007 servers that do not have WebDAV enabled? If so, then why are Snow Leopard Exchange access on the Mac, as well as Outlook 2007 clients on Windows through OWA, and phones through Exchange ActiveSync still working fine? They don't need WebDAV?

[Mickael Guessant]

That's it, they don't need webdav:
- Snow Leopard Exchange support is based on EWS and not compatible with Exchange 2003
- Outlook uses rpchttp (MAPI tunnel) to connect to Exchange over internet
- ActiveSync phones use the activeSync endpoint (after paying Microsoft the right to use ActiveSync)
- Microsoft Entourage is based on Webdav and compatible with Exchange 2003 and 2007, but probably not Exchange 2010
- DavMail is also based on Webdav and compatible with Exchange 2003, 2007 with Webdav enabled and not (yet) Exchange 2010

[SourceForge Robot]

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