Forward method in Outlook 2013
In Outlook 2013, things work a bit different as the Reading Pane is also a place where you can now compose emails. Therefor the Forward button is now disabled.
To still be able to use a Draft as a message template, you can use one the following methods instead:
Open the message via a double click first. Then either press CTRL+F while the cursor is inside one of the header fields (so not in the message body) or add the Forward button to the Quick Access Toolbar (QAT). It’s already listed as an option when you press the down arrow on the right side of the QAT.
Copy the message first. A quick way to create a copy is to use CTRL+C and then CTRL+V when the item is selected. You can then press CTRL+V again to create additional copies.
The Following is the best method and makes Outlook 2013 behave like Outlook 2010 for creating new emails, replying and forwarding emails
Disable the option for allowing composing in the Reading Pane. This will however also affect regular replies and forwards.
File-> Options-> Mail-> section: Replies and Forwards-> enable option: Open replies and forwards in a new window