Automatically email supplier when their certificate expires

Hi.

Apologies for the 6 months break.   I have had other projects to get onto and now finally have time to look into this.   So far, this is brilliant.  It does everything I need it to do.   However, one small problem.   When there are no dates entered into the spreadsheet,  it still send the email and should not. Please see below.

and also produces an error on the last column.

If I can stop the email sending blank or getting an error, this would be an absolute game changer.  I've tried ChatGPT and don't understand the results 😂

Thanks in advance. 😀