I applaud your instinct to read the words of the statute to determine its meaning. There are, however, certain rules and/or maxims you are missing that courts will apply to guide how even seemingly simple phrases are to be interpreted.
The language of the statute (52 USC 30121) provides that it shall be unlawful for a foreign national to make, or for a campaign to knowingly solicit, accept or receive from a foreign national, "a contribution or donation of money or other thing of value . . . in connection with a Federal, State, or local election." In interpreting the meaning of the phrase "other thing of value," there are two obvious principles of statutory interpretation that courts will apply -- ejusdem generis and the rule of lenity.
First, the ejusdem generis maxim provides that "where a class of things is followed by general wording that is not itself expansive, the general wording is usually restricted things of the same type as the listed items." An example of this maxim would be a statute that applies to "cars, trucks, buses, motorcycles, and other motor vehicles." If read in isolation, "motor vehicles" could technically refer to an airplane or the space shuttle, because both are vehicles that have a motor. But the maxim would counsel for excluding airplanes and the space shuttle from the list of regulated vehicles because the types of vehicles specifically listed all have the common trait of being land-based. Here, this isn't a classic case for application of the ejusdem generis maxim, insofar as there is only one specific term ("money") listed, but a court would nevertheless likely apply the maxim in this situation because the situation is similar to the classic application -- a narrow term followed by a broad one and, as set forth below, the limiting element of the one word is clear based on other contextual clues. Thus applied, the maxim would limit the meaning of the broad phrase "other thing of value" to mean "other thing of value that is similar to money." Applying that meaning here, "other thing of value" would, arguably, include things like precious metals, tangible items (like a car, plane, or boat), etc., but it would not include intangible things, like information. Moreover, because a stack of emails is unlike money in that it doesn't have an obvious extrinsic value outside of the context of the thing being regulated (i.e., the campaign at issue), a stack of emails would not be a "thing of value."
Second, the rule of lenity is a due-process based limitation on criminal statutes. It is a bit of a fiction (because no one opens the US Code for an afternoon of light reading), but the idea is that criminal defendants must have notice in the text of a statute that their actions were, in fact, criminal. Thus, in the event a criminal statue is vague, it will be interpreted narrowly to avoid any due process concerns with lack of notice. Here, the statute is plainly vague as to whether "any thing of value" includes information/emails, so a court would most likely construe that term narrowly to avoid any due-process based concerns.
Finally, it is also worth noting that the statue was enacted against the backdrop of concerns over the influence of foreign money into US elections. That's why the statute prohibits "contributions" and "donations." It would both strain the English language and bypass the animating spirit of the statute to say that the provision of information/emails is a campaign "contribution" or a campaign "donation," (particularly as to information considering it isn't a "thing" even if it had "value" in some sense of the word). Those terms more appropriately apply what the statute was designed to prevent -- undue influence of foreign funds in US elections -- than information/emails containing opposition research on a candidate and/or correspondence from the opposing convention.
I'm just spitballing here, but this is the basic outline of the argument, as I see it. I'm confident I could really put together a scintillating argument on this point if I had the inclination.
OK, that’s actually helpful. But, in response to the first explanation, why wouldn’t legislators use a phrase like “and similar things” instead of “other things of value” at the end of that list of prohibited items if they wanted to limit the scope of things that could have value? The phrase other things of value seems intentionally vague and broad. The second explanation sounds like it is a principle to protect defendants from over zealous prosecutors, which I respect.