If you have set up Office 365 and want your users to be automatically redirected to your company branded Office 365 logon portal here is what you need to do

1-dns-settings-for-office-365-www-redirect
Go into your DNS settings at your registrar

You may use the following destination for your www-forwarding in order to get to your portal:

  1. https://outlook.office365.com/owa/?realm=haukeberg.no

  2. https://outlook.com/haukeberg.no

Note that I can turn on URL cloaking, which means the user will allways see my domain (epost.haukeberg.no) in the URL header when he navigates the site. There are some benefits and drawbacks to this

If you can not find your WWW-forwarding settings, use a CNAME post instead. Here is what you need:

4-cname-post-for-365
If you can not find WWW-forwarding

The destination is:

  1. Outlook.office365.com

Result is as follows:

2-standard-login-365-no-branding
Standard Office 365 portal
3-custom-branding-office-365-portal
Already branded Office 365 portal

Adapted from: https://blogs.technet.microsoft.com/kpalmvig/2011/09/15/easy-url-for-office-365-owa/