G mail configured in 3 pc outlook, new mail is not getting equally to all 3

i have a gmail account configured in 3 outlook pcs
the thing is that whenever a new mail is received, all of the 3 outlook is not receiving the mail. it will be in any of the 3 outlook randomly.
all new mail is not getting received in 3 outlook equally

i hope it might be some setting in gmail which i am unable to sort it out.
kindly help