Right on! It is constant and unrelenting. And a dozen or more emails a day all offering all sorts of contests one can enter by contributing so much. Another aggravation with the emails is they offer links to contribute, some as low as $10, but when you click on it the only options start at $250 and go up. :(
As you say, blood from a poor stone.
I'm looking through my junk emails, and the first ten I've checked ARE NOT from Trump's campaign. One of the most annoying things about Apple mail and Outlook is that they show a screen name in the "from" and not an actual email address. Their actual return email addresses are generic "gomaga" type accounts, just trying to grift a few bucks.
In short, 98% of the emails and texts I get, and I get about 150 daily, are from organizations not related to Trump, but trying to raise money off his name.
It's like buying a MAGA hat off Amazon. Many of these distributors have nothing to do with Trump. In fact, they're selling cheap Chinese MAGA knock offs. Then, people get on twitter, and show the "Made in China" tag on the fake MAGA merchandise, and claim Trump is selling Chinese stuff.
ONLY contribute directly through Trump's official web site, and only buy MAGA merchandise through the Trump official campaign store.