​Considering Outsourcing Document Printing/Mailing – Recommendations?

As my small business has grown, handling all the printing, stuffing envelopes and mailing for things like letters, invoices, marketing pieces has become extremely time-consuming. I’m considering using an outside service that could take over this entire process.

The idea would be we just upload our digital files and order details to their system, and they print everything, do any finishing/folding, stuff into envelopes, apply postage and get the mail out for us.

For those who have used print/mail outsourcing services to handle business documents and correspondence, what has your experience been? Reliable quality and turnarounds?