Apple Support Discussions user "llhjunk1" reports:
"I have tested this function and find that email notifications sent from the file share dialog box are not transmitting for me. IF I copy and paste the share point URL and put it into an email with MobileMe or paste it into an email from Apple Mail, the email transmits and it is received. to recap, the issue relates only to sending the share notification directly from the MobileMe share dialog box."Possible workarounds
Unfortunately, this issue needs to be resolved by Apple. While users cannot do anything to fix the bug on their end, you can take precautions that will allow you some piece of mind knowing that your link was sent.
1. Copy the URL and send your own e-mail. When the MobileMe file share dialogue box appears, copy the link provided and create your own message containing the link. You will then have a copy of your sent message verifying that the e-mail was sent.Resources
2. Add your address to the recipients list in the file share dialogue box. By adding your own address you will be able to see if your e-mail sent properly. If you do not receive the message, you can assume your other recipients did not either. Go back and do the first suggestion.
3. Leave Apple feedback. By letting Apple know what issues you are facing, they are better equipped to make important updates to their services. You can leave feedback here.
Read this Apple Support Discussions thread regarding the inconsistent file sharing notification e-mail in MobileMe's iDisk.