CRM that can automatically respond and include a Outlook email thread?

A prospective client who currently uses O365/Outlook/Salesforce is asking if there's a way to automatically respond to an existing email thread after some period of inactivity with that thread.

i.e. If they begin a sales related conversation over email, and the client stops responding. After 8 weeks of inactivity they want to send them an email to check in, but want to be a reply to the existing email thread, and not a brand new message.

They say they are not necessarily tied to using Salesforce if there's another CRM that can do this.

Or is there one that could be customized to do this?