Re: [Evolution] Evolution and Exchange 2007 (aka 5.5) on Fedora - port 135

[Paul Smith <paul mad-scientist us>]

On Wed, 2008-09-10 at 08:23 +0200, Valent Turkovic wrote:
> > > The Evolution Exchange connector uses the Exchange Open Web Access (OWA)
> > > interface, which is essentially the Exchange webmail interface, to
> > > contact Exchange.  Thus, to use the connector you need to have the Web
> > > ports open (80 and 443, for HTTP and HTTPS respectively).
> > >
> > > However, the new mapi-provider backend talks to the server using
> > > Microsoft MAPI protocol, which is the same protocol that Outlook uses to
> > > talk to Exchange.  This protocol uses different ports, of course, since
> > > it's a different protocol.
>
> Before my company switched to new Exchange 2007 I could read email
> from wherever I was (over public facing owa through Evolution Exchange
> Connector), and if I understand you now this is not possible now
> because ports that are needed to do the communication are usually
> blocked by corporate firewall.
>
> Ok, I can use my email via Evolution now when I'm inside the company's
> LAN but before I had been spoiled by accessing my email from home or
> from anywhere else. Is there some solution to this?

The right answer is that your company should be providing a VPN for
remote access.  Having the Exchange server HTTP interface (or MAPI
interface) directly available through their firewalls to the internet
is... well, it's just not a good idea and we'll leave it at that.

The question is, can Windows users use Outlook when they are remote?  If
so, then you can use Evolution.  If Windows users have to use a browser
to read mail when they're remote then you will have to do the same.

The only solution that would allow you to continue to use Evolution with
only a Web interface is for someone to rework the Evolution Connector
backend so that it can parse the new HTTP format that Exchange 2007 is
using.  The problem with the model used by Evo Connector is that it
relies on the HTTP interface provided by Exchange.  However, Microsoft
can (and does) feel free to modify that interface at any time: there is
no backward-compatibility etc. issue, because the code is all on the
server and clients only have a browser to connect with.  They can
rewrite the entire interface with every release if they like.  And,
creating software to "bridge" between the HTTP provided by Exchange and
the functionality required by Evolution is not a simple task, at all.
It's a constant effort to stay current.  That's why developers are
moving to MAPI, which is a (more) stable protocol and much easier to
manage.