It took me a minute … you mean add the program icon to the Message? That would look nice and visually link it. Could also use the frame icon 0{PROP:Icon}.
IF Message('Please use File->Exit to quit |or minimize the window.', |
'eMail Timer', 0{PROP:Icon} ,'Minimize |Keep Open')=1 THEN 0{PROP:Iconize}=1.