Which Services Block Temporary Email Addresses? (Discord, Steam, Netflix and More)

"Please use a valid email address." You've typed a perfectly valid disposable address into a sign-up form, and the site refuses it anyway. What's happening is domain filtering: the service checks your email domain against a blocklist of known disposable providers and rejects the match.

Not every service does this, and the ones that do vary wildly in how aggressively they enforce it. Here's an honest rundown of where things stand, based on our own testing and user reports — with the usual caveat that services change their policies without notice, so treat this as a snapshot rather than a guarantee.

How Disposable Email Blocking Works

Most services don't detect temp mail through anything clever. They use one of three techniques:

Static blocklists — Open-source lists of known disposable domains (there are several on GitHub with tens of thousands of entries). Cheap, common, and always out of date.
MX record heuristics — Checking whether the domain's mail infrastructure looks like a bulk disposable provider.
Verification APIs — Paid services (ZeroBounce, Kickbox, etc.) that score an address in real time and flag "disposable" as a category.

The common thread: they block domains, not addresses. This matters, because a provider that issues addresses on rotating subdomains — tempy.email gives every mailbox its own generated subdomain like @17mur6.tempy.email — is harder to blocklist than one that funnels everything through a single well-known domain. Harder, not impossible: a service can still block *.tempy.email at the root, and some do.

The Service-by-Service Rundown

Usually fine with temp mail

Reddit — Historically permissive; you can even use Reddit without a verified email for basic browsing. See our Reddit use-case guide.
Substack and Medium — Newsletter platforms generally accept any deliverable address, since their business is sending you email, not verifying who you are.
Most SaaS free trials — Smaller products rarely pay for verification APIs. This is the sweet spot covered in stop giving your real email to free trials.
One-off downloads, whitepapers, coupon gates — Almost never filtered.

Hit or miss

Discord — Commonly reported to reject well-known disposable domains at sign-up, and accounts created with flagged addresses may be asked to re-verify later. Fresh or lesser-known domains often get through. Details in our Discord guide.
Steam — Account creation typically works with a temp address, but think hard before doing it: Steam Guard codes and password resets go to that email forever. A disposable address on an account holding a paid game library is a self-inflicted lockout. See the Steam use-case page.
Netflix — Sign-up itself is usually lenient about the email, but a streaming subscription is a paid, ongoing relationship — billing receipts and password resets need a mailbox that still exists next month. Our Netflix page covers when temp mail makes sense here (mostly: trial exploration, not your main account).
Amazon — Registration often accepts temp addresses, but Amazon's fraud systems weigh many signals, and accounts that look throwaway get flagged or asked for phone verification. Order confirmations also live in that inbox. More in the Amazon guide.

Usually blocked or a bad idea

LinkedIn — Aggressive about account quality; disposable domains are frequently rejected, and even when sign-up succeeds, verification challenges tend to follow. See LinkedIn.
Banks, payment processors, government services — Blocked, and rightly so. Never use temp mail where money or identity is involved.
Facebook / Instagram — Meta invests heavily in fake-account detection. Temp mail sign-ups often work initially, then hit checkpoint verification (usually a phone number demand) within days.

What to Do When You Hit a Block

Regenerate the address. With tempy.email, each new mailbox gets a different generated subdomain. If one is on a blocklist, the next may not be.
Check whether verification is actually required. Some forms reject the domain client-side but never send a verification email at all — the sign-up may still go through.
Decide if this account deserves your real email. A block is a good prompt to apply the rule of thumb: ongoing paid relationship, real email (or an alias — see disposable email vs email aliases); one-time access, temp mail.
Don't fight blocks on accounts you'll keep. If you're going to store value in an account — game libraries, purchase history, a professional profile — the email on file is your recovery lifeline. Losing it is worse than the spam.

One more troubleshooting note: if a service accepted your temp address but the verification email never shows up, the cause is usually sending delay or a silent drop on their side, not the temp inbox. Our FAQ on why you didn't receive an email walks through the checklist.

The Bigger Picture

Blocking disposable email is a losing arms race for services — the lists are perpetually stale, and legitimate users get caught in the crossfire (plenty of privacy-focused custom domains end up on those lists too). But it's the reality of the landscape in 2026, and knowing which services enforce it saves you the trial-and-error.

For everything that doesn't block temp mail — which is still the large majority of the internet's email walls — grab a free address at tempy.email and keep your real inbox out of it.