you can controll the sending policies, but the reciever may have his own policy which his admin has to configure.
with file-formats, that are known to be blocked often, i suggest to rename the file and send it.
rename file.cpl
to
file.ren2cpl
ren2 is easy to remember as rename-to
then you successfully go through all policies.
tell the recipient to re-rename the file in the email.