Opening emails in SharePoint
As part of a recent project we used SharePoint to store emails, both via incoming emails and one of the 3rd party drag and drop tools.
Most users were happy with the solution once we had updated the MIME types to allow emails to be opened rather then downloaded, but some still mentioned they would rather that email opened directly from SharePoint rather than seeing the yellow download bar that Internet Explorer puts up.
A bit of digging around on the internet came up with the solution from this Microsoft KB article
http://support.microsoft.com/kb/2678934
To enable emails to be opened directly from SharePoint the trick is to disable the Internet Explorer download bar for email file types, to do this add the following registry key to your local machine.
HKEY_CURRENT_USER\Software\Microsoft\Windows\Shell\AttachmentExecute\{0002DF01-0000-0000-C000-000000000046}
then run the assoc command below to get your .msg file extension type (mine is for Office 2013)
Now add that file type as a zero length binary value to the key created above.
Emails will open directly from SharePoint.