I went to jmail.world to see the emails between Epstein and William Riley and maybe see some context, and I did. I also corrected their spelling along the way, but linked the original documents for each.

The date on this particular email is April 18, 2011, but first I wanted to see who William Riley was. At a certain point he is giving Epstein his vehicle registration and listing his work email as "whr[@]rileykiraly[.]com" which points to a fairly small St. Petersburg, FL private investigation firm.

That he was doing PI for Epstein is clear in the back and forth, but the actual reason appears in the email Epstein sent Riley on April 2, 2011 where after failing to get whatever documentation they were looking for by other means, Epstein tells Riley, "I need to prove that she did not work at Mar-a-Lago until she was seventeen," and Riley replies with the suggestion, "I say we try Mar-a-Lago straight up and see what they say."

Then on April 3 there is another exchange where they're debating about how "personnel" at Mar-a-Lago should be approached, and after Epstein names a guy he used to know there but "Donald fired him" they mutually agree that a personal visit is best.

On April 7, Epstein wants an update, asking Riley if he's had any luck with "Roberts" (Virginia Giuffre's maiden name and the one by which Epstein knew her) and referencing Mar-a-Lago; Riley replies that he thinks they have someone checking the files there.

On April 13, there's another email from Riley to Epstein saying "they don't keep records going back that far" but he's "trying another avenue."

And then there's the email from April 18, the one featured in the Rawstory article OP posted. The context is clear.

Epstein and Riley, working together to prove Virginia Giuffre was at least seventeen when she was recruited from Mar-a-Lago, don't want to ask Donald Trump for records pertaining to Virginia Giuffre unless there is no possible alternative to calling him, because they have now exhausted all the other methods of proving this that they've tried. This is them checking with each other to see if either of them have any further bright ideas before picking up the phone and calling Trump, which they apparently do not because the emails end here.

And that's it. The next emails between them are from the same summer, where William Riley is trying to get paid for all this.

Meanwhile, 2011 is when the Prince Andrew thing started to blow up on him, and he lost his gig as UK trade envoy in part because of his relationship with Epstein. Virginia Giuffre had already sued Epstein, but in 2010, the year prior, also decided to go public with her allegations about Andrew, and of course the photo came out around then as well.

Between the dates of the media articles and the picture with Andrew coming out, these emails, and the status of her lawsuits, it seems pretty clear that all of this effort is for Andrew: by getting proof Giuffre was seventeen when he recruited her from Mar-a-Lago, Epstein hoped to put Andrew in the clear in terms of her age.

EDITED to correct defunct EFTA link for April 7 email