Guide

Why some sites block temporary email

A site that rejects your address is not being rude. It is trying to cut abuse, and it has lists of domains that look temporary.

Updated 2026-10-02 · Emailsify

How blocking works

Services keep lists of known temporary domains and check the part after the @ when you register. Some also check whether the domain only accepts mail and never sends it.

Why they do it

  • Bogus sign-ups and free-tier abuse.
  • Referral and promotion fraud.
  • Wanting a way to reach the user later.

What to do

  • If you only needed to look around, move on.
  • If you want the service, register with an address you control.
  • Do not try to disguise a temporary domain: that breaks the terms of most services.

Frequently asked questions

Can you guarantee an address will work everywhere?

No. Acceptance is the service's decision and changes over time.

Keep reading

How temporary email works under the hoodA plain-English walkthrough of how a temporary inbox receives mail: DNS MX records, SMTP delivery, storage and expiry.How to receive a verification code without your real emailStep by step: get a temporary address, use it on a sign-up form and read the code. Plus what to do when a site refuses it.Temp mail vs email alias vs plus addressingThree ways to keep your real address private compared: temporary inboxes, forwarding aliases and plus addressing. Pros, cons and when to use each.