People I send emails with attachments are not getting the attachments or their email shows attachment but nothing there.
Mac OSX 10.6.8 Safari 5.1.2 Verizon email 2.0
Using another email account it works but not verizon.
What kind of files are you trying to attach?
Is it all recipients having this problem or specific one(s)?
Could you possibly post a screenshot of the sent message from your side and a screenshot of what the recipient sees?
What happens if you send one of these messages to yourself?