Tip: If you copy and paste the exact text of a message you’ve received with quotation marks into the Tumblr search bar, it turns out you can see pretty much every other instance that that message has been received and responded to.
If you get a message out of the blue from someone asking you to donate or share their fundraising posts, I would strongly recommend that you double-check to make sure they haven’t already spammed a dozen other people with the same message, as the odds are pretty likely they’re a scammer if they have.
I’m also pretty sure that in light of this post, this particular scammer will switch to requesting that you respond to their ask privately to avoid being caught spamming people in this way - if that’s the case, you can pretty much guarantee that they’re trying to scam you. ETA: Folks have made the point that some requests for aid could be genuine and to not rule out every request for a private response, which is fair! As always, double-check to make sure they haven’t already spammed or been called out for scamming people, ask for further info, and if they refuse - delete, block and report, baby!