How to unlock Blitz Play

This seems to be a bug. The developers are currently working on a fix. I solved this issue by loading an older save game and restart from that point. If you don't have an older save game you can wait until the release of this fix. Don't think this fix will be published soon because of all the issues with GTA online. Or you always can start over...

After the mission "Mr Philips" with Trevor, you should see an orange question mark appear near Sandy Shores - this is the Special Bonds mission where you meet Maude.
About 5 minutes after this she sends you an email with a map of the location of Ralph Ostrowski, the first of the "Bail Bonds" missions.

Now, I did this first mission successfully, and then she sent me another email for the 2nd Bail Bond mission, but it has since disappeared! Same problemo I think. I had to google for Larry Tupper's whereabouts, and sure enough he was there, even without the email.

As long as you've met Maude already, I think you are going to have to google for the whereabouts of Ralph and I'm sure he will be waiting for you there, even though the email has disappeared/or you never received it.

Just in case you are wondering, Ralph is located at:

At the bottom of Davis Quartz Quarry (southeast of Sandy Shores, other side of Senora Freeway)