I am experiencing the same thing as the OP, and I wonder how these ICO's got my email address.
Read the thread. They obviously bought the hacked details from the forum leak:
No, but the forum database was hacked and leaked and these spammy scammy scumfuck ICOs just buy the mailing lists. I keep tagging any Icos who send me emails so hopefully they'll get the message.
Probably the ones who sells your email are ICO and sites where you submitted your email and slack (mostly slack because it's broken AF)
It's not that. I've never signed up for an ICO but I keep getting the spam. They're just buying a mailing list from somewhere.