However, a cancellation stamp on a piece of Standard Postage mail could be remedy if the response rates are effected by postage in your market.Really its what the Post Office guarantees with First Class that makes folks spend the extra money: guaranteed return mail and a 3-5 day delivery time.Standard Postage, on the other hand, can take anywhere between 3-30 days to deliver and you are not guaranteed return mail, BUT the benefit is that it is cheaper per mail piece therefore you can have more mail pieces out.

Whether they paid by carrier pigeon, a drone, or however they chose to send it and deliver it to me, was on them.  

Too late to do this in your case, but the thing to do would have been to write into your offer that 1 of the units (even a specific unit) be delivered vacant at close of escrow ... then you wouldn't close until/unless the unit was vacant, and it is the seller's issue to sort out, not yours.

Hi all,I am 10 days away from closing on my 4-family property, however, I'm unable to actually get into the property to get quotes on the renovations.There are 2 units that will be delivered vacant and I have a small list of renovations I would like to get done ASAP.The listing agent is not answering my agent and the seller is seemingly always "away" or "out of town".

If unit is vacant at time of your offer, and you do not want them to place anyone in it them your offer must be contingent on it being delivered vacant.

However, speaking very generally - typically in California, once you sign the lease and the tenant is delivered a copy, and once the tenant delivers the agreed-upon Move-In Costs in the agreed-upon time period (typically deposit + first month's rent), that's the end of it, you're locked in, handcuffs and all.

They design, and deliver....best prices I have yet to find and top quality.Here is a pro tip:  Spend real money on getting top quality signs.  

There are plenty of groups that over promise and under-deliver. 

So, having all the units in good shape will obviously maximize your sale value  (more so than NOI since it is a 4-plex, which makes it residential property which will be valued off of comps), and having at least 1 that could be delivered vacant would make it more attractive for an owner occupant buyer.

Have an open and honest and discussion with them, delivered with care and concern.