Problems with Apple mail (Not sending complete message)

Hi all,

I have Apple mail to access Gmail and a business mail account.

Sometimes, both accounts don't send the complete e-mail.

Example, it is sent a message with several lines and an attachment. Some text is written after this attach, and the receiver of the mail doesn't see the entire e-mail, only sees the text until the attach.
This can also happen without attachment. The bottom lines, are not send or not received... Until now I didn't understood the logic.

I've already run Onyx and didn't solve the issue...

Any ideas?