Delete messages out of the send task

Hi all,

we are sending mails using a outlook client on a server. In the past we
occasionally received the error message „Could not resolve the message
recipients“. I debug the code and find out that one of the recipients email
address was not valid because the name part of the address was empty. I
adjust our code for sending the mails to generate a name out of the
SMTP-Address. But during debugging I used five times successfully the command
mail.send.
Because I used existing email addresses to find this bug and it’s not
allowed to send this messages to the customer. I disconnect the server from
the network and outlook try to send this messages. On the server we don’t
save outgoing mails in the outlook folder.

How can I delete this messages out of the send task?

Thanks for help

Ron