>>Borislav,
>>
>>I think your best option would be to create your own preview form with a send button and then use the code you already have to send the e-mail.
>
>They will never be sure what I send :-(
>They could view what I showed to them, but If that is what I send ...
>We develop salary application that contains many private data, so they have rights to be suspicious to everyone :-)

You preview it and send like Hugo said, but also CC them they then know what got sent, best of both the worlds I guess.