OwnerRez does not support email blasts - that is, marketing emails sent to all previous guests, or to a subset of them. At the moment, OwnerRez only sends emails one at a time, to a particular guest.
However, that doesn't mean you can't do it! We do store all emails from all your guests, which you can see in the Reports area in our Email List report.
You can then export this report to Excel, so you get a spreadsheet which can be imported into a newsletter tool like MailChimp.
We also have other screens (such as the Booking list view) which can generate Excel or CSV exports that can be used the same way.
This allows you to get the data out of OwnerRez, and then use it in a tool designed for doing email marketing.
Don't forget, our reports can provide much more useful information than just the bare email address. For example, our Email List report includes fields for what the guest did last, such as "inquired" or "booked", and a friendly date. That way, you can start your mail blast with a personalization like this...
We wanted to reach out because you last inquired with us in March of 2018.