Email campaign software?

I want to initiate an email campaign to all new hires that sends them various information on a daily basis over the span of a couple weeks. It seems like a relatively simple thing to do, but I can’t find a reasonable solution. I don’t want to pay a monthly fee for a third-party marketing company to do this, and I can’t find an add-on in Outlook that would allow me to program a scheduled sequence of time-delayed emails.

Does anyone know if something like this exists?

Delayed sending is built into 2013: Delay or schedule sending email messages - Microsoft Support

Probably earlier versions too.

You’d still have to manage the recipient list yourself.