Here is a great tip, for those of you who might not know it already:

To confirm that an end user is receiving mail to their device, send them an email with <confirm> as the first word in the subject line. You can write anything else in the subject as well, as long as <confirm> is there first. For example,

"Subject: <confirm> Test from BES Admin, OK to delete, no need to reply"

As soon as the message hits the user's device, a confirmation receipt is sent right back to the sender, without any user intervention required.

This is pretty handy when activating a user who you can't reach, to make sure they are getting mail to their device.

Sometimes you will get a confirmation back from yourself as well, so just be careful not to confuse that with one from your user.