You can't control the messaging when the marketplace sends constant emails, mailings, and robo-calls notifying them of a message in their account, wrong 1095's, password resets, or follow up on document submission.
The client is more afraid of the gov't than they are of losing your relationship.
Had a lady call me today that was audibly shaken by all of the letters emails and other stuff that she received concerning her tax filing for last year. She was very sweet, but also sounded "scared".
I don't think a birthday card from an agent or a "checking in with you" phone call means a whole lot these days for "on-ex" clients.
I'm scared to death of the Government as well. Heck, I'm even scared of the carriers...if you're suspected of a CMS violation, it makes you feel like you're under Pinochet's rule.