How do I set up my e-mail on Libre Office?

I have just down loaded Libre Office and want to use it as my default e-mail.

LibreOffice has no mail client, so you cannot read your emails using LibreOffice. You could use it to send emails, but only as a mail-merge (sending personalised messages from a template to one or more recipients).

If you are looking for an open source mail client, try Mozilla Thunderbird.

See this: Is there a LibreOffice Outlook replacement