My method is to message (text, phone, email etc.) landlords who have posted to local classified sites looking for tenants, and ask if they would consider selling their rental property.

That's not a method I'm familiar with, and a quick google search brought me to many MANY pages where they tried to sell me the system without really explaining to me what the system is.

Or any methods I can use that can help me locate them?

Aside from traditional lender financing, I'd like to make sure I've explored options to put less money down than 20% and potentially find a better rate than at a local/commercial bank.  

I've been in the business for years, got out for a while and explored other avenues, but got back in - because I enjoy helping and teaching others.

I am eager to explore all that BiggerPockets has to offer and look forward to great experiences.

Definitely take the time to fully explore all that this website has to offer as there are endless learning tools touching on the numerous aspects of real estate investments.

Imagine asking a real estate agent to only accept a 1% commission because you'd like to pay less and have more equity in the house ;) Both turnkey and traditional methods are great, but for different reasons.

[Unless landlord-tenant law for your jurisdiction requires it, don't send certified mail return receipt requested or at least don't rely solely on this method.

I recently purchased my second property using the BRRR method and am currently looking at doing a cash out refinance.