What Mr. Trump actually said in the press conference:
"If they [the Russians] hacked [referring to the recent DNC hack] they probably have her 33,000 emails. I hope they do. I wish I had that power. I'd love to have that power.
They probably have her 33,000 emails that she lost and deleted. You'd see some beauties, so we'll see."
And later in the press conference:
"Russia, if you're listening, I hope you're able to find the 30,000 [Clinton] emails that are missing. I think you will probably be rewarded mightily by our press. Let's see if that happens. That'll be nice."
And Mr Trump tweeted later:
"If Russia or any other country or person has Hillary Clinton's 33,000 illegally deleted emails, perhaps they should share them with the FBI."
Observations:
i. Mr Trump did not "call on" anyone to "hack Hillary".
ii. The e-mails to which Mr. Trump refers are the State Department correspondence which The Hillary has admitted her staff destroyed, before turning over the remaining undestroyed e-mails to the State Department [which should have held all the e-mails in the first place].
iii. Mr. Trump did speculate that if Russia, in fact, hacked the DNC, they probably have the Hillary's "destroyed" State department e-mails as well. [ n.b. No one has submitted any evidence that Russia is behind the DNC hack. - DD]
iv. Mr. Trump then speculated that if Russia were to turn over The Hillary's "destroyed" e-mails, the US Press would reward them. He later clarified in his tweet that anyone who has The Hillary's "destroyed" e-mails should share them with the Federal Bureau of Investigation.
v. The Hillary has previously assured all Americans that the "destroyed" e-mails comprise " 'personal correspondence' – ranging from plans for her daughter’s wedding to her yoga schedule." Who knew, . . . Hillary does yoga !
Conclusions:
i. Mr. Trump has not directed anyone to commit espionage. He has, in fact, requested anyone who already possesses The Hillary's 33,000 personal e-mails, which she and her staff destroyed anyway - presumedly for personal reasons, to share them with the FBI.
ii. If, as The Hillary assures America the "destroyed" e-mails pertain to only personal family matters, there cannot be any possible harm to the Country upon their discovery, submission to the FBI, and subsequent release.