Why are my push notifications expiring?

Hi.

I received this message today and I'm completely confused on what it means, and what to do.

I don't recall setting up any certificates, so can someone please explain what's happening here and how I can resolve it?

When I try to open the server app, I'm told that it cannot be opened on this type of Mac. Lion Server came preinstalled on my Mac Mini though.

Message:

The following Apple Push Notification Service certificates, created for AppleID will expire on June 18, 2013.You can renew your certificates with your Mac server administration tools.

server.local - apns:com.apple.calendar

server.local - apns:com.apple.contact

server.local - apns:com.apple.mail

server.local - apns:com.apple.mgmt

Thank You,

Apple Push Notification Service

the alert