I want to add Emails to navigation so It can be used like any other entity. Editing sitemap is not a problem but it does not work in the expected way.
First, of all it shows all entities, not emails only. And consequently there are filters for other activities which are unwanted.
How do I make email-view that does not show other activities?

Create a new view in CRM showing the records you wish to see
Create a HTML web resource, with an iFrame pointing to the URL of the view you just created. It will look something like this
/advancedfind/advfind.aspx?AutoRun=true&QueryId=%7b495B7974-58AC-E234-92D4-EE155D107003%7d&ViewType=4230&etn=emailPoint your sitemap to the new web resource