VB Help Please

Hi,

I have a visa expiration tracker that I'm currently working on. 

I've managed to set up conditional formatting and if statements to highlight when a members visa moves to 6 months from expiry.  =IF(D2<=-182.5,"","Expiring")

What I'm trying to do is get a pop up notification on opening the spreadsheet or alternatively an email notification for when a record is indicated as Expiring.

Any help would be greatly appreciated.