Annnd as if to triple underline these concerns and write them in 100ft high neon letters, I just started getting cryptocurrency specific spam, at an email address I use very sparingly for bitcoin stuff. Somebody I trusted just fucked up, sold, distributed or lost control of my info. I hope it's one of the ones that only needed an email address.
I have the same (personal) account setup @ cryptomex.io> and I'm not receiving any of what you're describing. Yes, cryptomexio+username
@gmail.com (
or-wherever-youremail@whatever.xxx) is fine to use for signup, We'll ensure all communications goes there, without changes to the email address.
Protect your email address the same as you would your identity, it is sacred (IMPO). Do not hand it over to just anyone. And if you're going to do that, utilize the tools provided. Absolutely identify breaches in your trust-base for sending of unsolicited emails and make it public without prejudice. That, or ask your email provider to update their spam filter.