https://github.com/RaymiiOrg/certificate-expiry-monitor

This is a free web app, unmaintained, to monitor and alert subscribers to expiring SSL certificates.

https://virtualarchitects.com/cem

Hostname, like www.virtualarchitects.com

1. Add a domain to be monitored
2. Check your e-mail Inbox for a message from noreply@virtualarchitects.com
   1. Check your spam filter, if necessary
3. Click the link to confirm your Certificate Expiry Monitor subscription
4. Check your e-mail Inbox for another message from noreply@virtualarchitects.com
   1. Check your spam filter, if necessary
5. Verify that the domain is subscribed

1. Click the unsubscribe link in messages you receive from Certificate Expiry Monitor

You can also craft an unsubscribe URL, if you know the domain ID, in the form:

https://virtualarchitects.com/cem/unsubscribe.php?id=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx