How to redirect Record link to site page in email

Appian does not support redirection of a link. Is this a custom email? If yes, why not put the link to the page in there?

Could you clarify what you're looking to accomplish? If you already have the URL to a record in /tempo, but you want it to instead load in a Site, you can substitute the "/tempo/records/item/" part of the url with "/sites/<site name>/page/<page name>/record/"