Delay sending to many recipients in one message

[Ed]

I have a client list of about 800ish. I want to start sending them regular
emails.

Sending that many at the same time creates problems for me in Outlook and
through my internet provider.

Is there a way to send one message to mutiple email addresses on a delay? So
that the same message is sent out one at a time to every email address in the
to/cc/bcc.

Thanks,
Ed