I’m not too sure, maybe? If the tracking pixel is on a domain known to serve ads or trackers, it might, but if it’s on a legitimate domain (e.g. your ISP’s) I don’t think it can, since you’d have to have added the ISP’s domain to the Pi-hole blacklist
Email aliasing services, which are genuinely good services to use, strip those pixels from inbound emails. At least Firefox Relay, Addy and SimpleLogin do
I’m not too sure, maybe? If the tracking pixel is on a domain known to serve ads or trackers, it might, but if it’s on a legitimate domain (e.g. your ISP’s) I don’t think it can, since you’d have to have added the ISP’s domain to the Pi-hole blacklist