A couple of days ago I got an alert from my site (https://checkmysite.io) letting me know that the SSL certificate for a user who signed up for SSL monitoring was going to expire in 7 days.
I set up this alert so that I can personally reach out in these circumstances to make sure the site owners are aware of the situation. The system does send automated email reminders 1, 7, 14 and 28 days before a certificate expires but emails are easy to lose track of or end up in the junk folder.
Anyway, I reached out to this user to let them know and when they replied, I found out it was a client I had worked with several years and 3 employers ago. The feedback they gave was very encouraging, they found the service useful (including the personal outreach), asked for a bit more information tailored to their circumstances/size and gave a couple of suggestions for improvements and blog posts.