Can't send mail from kontact using davmail

I moved to Arch Linux recently with KDE, and tried setting my organization email account on Kontact using davmail.
It's not my first time, and I just used this steps as usual:
http://osdir.com/ml/kde-pim/2011-07/msg00146.html

Everything was setup except I couldn't send email and received the following error:

Error : davmail.exchange.ews.EWSException: ErrorSendAsDenied The user account which was used to submit this request does not have the right to send mail on behalf of the specified sending account

After lot of investigation, I found out that somehow "davmail is not sending the right "From" address in new versions".
That's Ok, except I have an old davmail server, that wasn't updated for some months, and it worked before I moved to Arch.

So I tried to check the Kmail side, and after a lot of time, came up with this note in the documentation:

The way of sending messages configured here will be used for your default identity and for all other identities that do not have their own way of sending messages. You can use different ways of sending messages for different identities by selecting the Outgoing Account check box in the Advanced tab of the Identities page.

Kmail Identity settings

Let's check my identity then! And I've found the culprit.
Go to Configure Kmail ->  Identities -> Choose your Identity -> Modify.
I had no email address set in my Identity, right after setting it up, the emails sent successfully!

Not sure why it happened, maybe some change in the newer version of Kmail. But that fixed it for me, and hope does the same for you!

Push emails (ActiveSync) suddenly not working on server 2003

Today a small business server 2003 was shut down unexpectedly (Simple electricity issue). After the server came up, the ActiveSync was no longer working. What I mean is that people who had their phones configured no longer received emails automatically by push. However the emails did sync, after going to the email app, and refreshing them.
So what's going on? Actually it's pretty simple for people that know where to look, unfortunately I forgot about the order of the things to check, and it took me a bit longer.
If you go to the Application log in Event Viewer, you will see the following error:

IP-based AUTD failed to initialize because the processing of notifications could not be setup.  Error code [0x80004005].  Verify that no other applications are currently bound to UDP port [2883], or try specifying a different port number.

Or this:

 IP-based AUTD failed to initialize.  Error code: [0x80004005].

So what's the solution?
Just restart the DNS Service. Everything was ok after that.

But, the problem may come back again. So here's the permanent solution, after reading more about that on this page, you may need to add the following ports as reserved in the registry:

• 1645-1646 - Used by IAS
• 1701-1701 - Used by L2TP
• 1812-1813 - Used by IAS
• 2883-2883 - Used by AUTD
• 4500-4500 - Used by IPSEC

Add this to the following registry:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\ReservedPorts

Now restart the server to make sure everything is fine.

Hope it helped somebody.