Exchang 2007 OWA

There is a previous fix that worked in the EE question:
https://www.experts-exchange.com/questions/23181722/OWA-getting-a-http-400-Bad-Request.html 

I disabled basic authentication and enabled forms based authentication. Now it says my username and or password is wrong.

Did you read the entire thread, or just the first post - the solution that worked (and was the accepted solution) was to remove and reinstall OWA.  Look further down the thread.  I'm not guaranteeing this will work, but it did for this question.

Also you can try re-applying the Rollup update that you have. As of now Rollup update 9 is the latest one... you can try applying the same... you can dowload it from http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=55320be2-c65c-48bb-bab8-6335aa7d008c

I read the entire thread and I removed owa and rebuilt it. Now when I use basic authentication it lets me in but when I try to send an email it says, "Microsoft Exchange issued an unexpected response (404)." If I use forms based authentication I cannot log in at all.

Have you installed Rollup 9?
http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=55320be2-c65c-48bb-bab8-6335aa7d008c 

I installed rollup 9 and am having the same problem.

Please try the following.
Extract from http://social.technet.microsoft.com/Forums/en-US/exchangesvrclients/thread/5c3b9041-a479-4979-a176-a11e8cbfc55f
After research, and much head-scratching, it turns out that the problem occurs if the URL used to access "OWA" does not exactly match the external URL configured in "Exchange 2K7".  This explains the problems that other people reporting this issue elsewhere have experienced, where the problems seem to have gone away after disabling and re-enabling "Outlook Anywhere" (and re-entering the external URL).

So, if you're experiencing this problem, here's a suggestion:
1)  Fire up the "Exchange Management Console"; expand "Server configuration" and select "Client access".
2)  On the task panel on the right, you should have the option to "Disable Outlook Anywhere" - click on that.
3)  Once the task has completed, you should have the option to "Enable Outlook Anywhere" - click on that.
4)  You will be asked for the external URL - type in exactly the URL you wish your users to use (including any port number, if you're not running on the standard SSL port of 443).  E.g., "https://server.domain/" (you don't need the "/OWA" etc. on the end) or "https://server.domain:port/".
5)  Once that task has completed, retry your external access.

Your mileage may vary, but at that point our access worked.  If I change the external URL to any of the other possible alias names for our server (there are a few), everything returns to "HTTP 400" errors.

when I enable outlook anywhere and try to put in https://mail.domain.net I get the error that it is not a valid hostname.

looks like I had to leave the https part out and just put in mail.domain.net then it took, but I am still getting the http 400 errors from external computers.

I find this odd but this is what I just did. I tried using https://mail.domain/owa and when I tried to log in I got the HTTP 400 error. Then I logged in with the https://ipaddress/owa and I got in just fine. What is going on with that?

What did you set the certificate up using?
If you used the IP Address, then you need to re-issue the certificate.

It is the default issued certificate.

Can you opne up IIS on the server and then select the server in the right-pane.  Then on the Feature/ Content view area, double click on the Server Certificates and see what it says.

What info do you need?

Is the name on the cert an IP address or the FQDN that you are trying to access?

If I go under server certificates the name is Microsoft Exchange.

Could there have to be a different port open on the firewall??

The firewall needs port 443 opened.
For the certificate, the name of the certificate should say something like mail.yourcompany.com. (see attached image)
If not - you will need to create a new certificate.

2007-Certificate.jpg

no it just has two the say microsoft exchange under the name column.

What do I need to put in for OU?

When creating a new cert that is.

mail.yourcompany.com or whatever you wish to use as the FQDN that is setup in DNS so that the FQDN points to your server.

I created a self signed cert. Now how do I apply it.

Here is a full run down of Certificates in Exchange 2007 from Simon (Mestha) one of EE's leading Exchange Experts.
http://blog.sembee.co.uk/archive/2008/05/30/78.aspx 

can I just set up owa to work over http instead of https?

The MX records through Godaddy were set up wrong. Once I got them setup right everything works great through https. It was weird because it doesn't affect http for OWA just https.