The obligation to mediate, unless otherwise agreed, will terminate if the entire dispute is not resolved within thirty days of the date written notice requesting mediation is delivered by one party to the other at that party’s last known address (physical or electronic as provided in § 26).

It has surprised us delivering nearly $60k in gross revenue annually.

Honestly once the doc was signed, most of deal was on me to deliver. 

Are STRs in this area still delivering strong cash flow?

You said in your post  "If the notice was delivered by mail then the notice period begins when the Tenant actually receives the notice."

The townhome should be delivered in July so hopefully if that is on track we'll have a better idea about Bennah Oaks!

I have no experience with this group but just visited their website. 

This is a straightforward process that we’ve followed to consistently deliver high-performance properties, and it does not require secrets or gurus.

We specialize in short-term rental investments through our integrated real estate, mortgage, and property management services, delivering expertise at every stage of the process.

I believe that you don't get returns (failed to deliver) with bulk mailers so you don't know which addresses are bad.That's the simple stuff.My advice is to do various mailings that you or some prepares locally, that go out immediately, using 1st class postage.