I want to know the support end date of aspNetMime version 2.8.
The developers don't offer any information regarding the end support date for aspNetMime version 2.8.
You can download latest version from the following page: http://www.advancedintellect.com/download.aspx
And you can check the FAQ and documentation on this page as well: http://www.aspnetmime.com/documentation.aspx
It appears that version 2.8 doesn't appear on website, since version 3.0 has been released, but you can contact the developers to get the support date for the product that you have: http://www.advancedintellect.com/contactus.aspx