When sending of an email fails and an exception is thrown (i.e. mail server not available) the renderer seems to get into a wrong state.
<s:link> present on the page get the application context "project". So "/myseamapp/foo/bar" becomes "/project/foo/bar".
If the action that is trying to send the mail is called by <s:link> this link gets the path of the email view itself (including the "project" application context).
I've attached a Bean sending the email, the email template (/test.xhtml) and a simple view.
This is the mail session configuration from components.xml
<mail:mail-session host="localhost" port="2525" username="test" password="test" />