Outlook- Duplication of outgoing messages

[jeff59]

Facts:

1. I send the "initial outgoing message with content" to a recipient, it is
properly received by recipient.

2. Within 5 minutes, Outlook automatically sends a "duplicate message
header, with no content" to the same recipient again. Thus, there is
duplication which needs to stop or be disabled.

Question:
1. Can you please provide instructions in the Outlook mail settings to
disable this automatic second e-mail.

Pls respond to (e-mail address removed)

Thank you