Custom trigger query

Hi I understand it would require some custom coding, but can I get an opinion on whether this would even be doable before I start?

So basically what I want to do is have a name and email as the author for each page (large company where staff send in their own content) and, using this custom trigger and whatnot, an automatic email would be sent to them every 6 months or so reminding them to review and update their content? To clarify, the staff don’t have WP accounts and have to request us (web team) to update the pages.

I’m really just looking for a yes or no at this stage but any advice about how to get it up and running would also be appreciated. My original thought was to only send the email IF the content hasn’t been updated in 6 or more months, however a blanket ‘every 6 months’ would probably be easier to implement.