It is happening even more frequently that some of our users find that their attachments have been sent with a size of 0 B, then the recipients get an error because the attachment is present but empty.
The sender realizes that the attachment has been sent with a 0 B size only after the mail has been sent, when he looks for the mail into the 'Sent' folder.
I cannot figure out how this happens and I cannot reproduce this behaviour.
Users are all using ZD 1.4 and ZCS is at its latest version.
Can you guess how it can happen?