[lategloriousgnu]

You need a valid phone number to create a gmail account, and you can only have a few accounts attached to the same number. Google is "trusted" because they actively try to prevent spammers from joining their platform. Disposable email platforms don't, they let you create as many as you like.

[franga2000]

At least a third of spam registrations on a platform I run come from Gmail addresses, with another third from yandex and yahoo. They also all went away after we implemented a nearly trivial captcha in the registration flow.

Seems to me that 1) Gmail accounts aren't that hard to farm 2) most spam comes from free webmail providers not disposable email and 3) a captcha will solve most of your problems and if it doesn't, it means your site is being specifically targeted by someone with cash to burn, so you can assume that they'll have emails that aren't on the blacklist. At that point, invest in detection and moderation.

[tmitech]

>You need a valid phone number to create a gmail account

This is 100% not true. Yes, the main site will require it, but there are legacy "portals" that allow signup without a phone number. No, I won't link to said portal.

[sahkopoyta]

Ok my bad gmail was not a good example. Lets go with outlook account then. Just tried and it definitely doesn't need phone number. And I wouldn't consider outlook disposable platform.