Yes. Mail21.cc is a known disposable email service, so block it at signup. Mailboxes expire within minutes and any existing Mail21.cc account should be treated as a fraud signal.
Every check returns one of three clear outcomes so you know exactly what to do with the address.
The mailbox exists and accepts mail. Send with confidence, the address is deliverable.
The mailbox does not exist, is disposable, or will hard-bounce. Remove it to protect your sender reputation.
The server is catch-all or greylisting, so existence cannot be confirmed. Send selectively and watch engagement.
mail21.cc publishes 1 MX record. The primary mail exchanger is inbound-smtp.us-east-1.amazonaws.com, hosted by amazonaws.com, and it is currently reachable and answering SMTP. Mail is routed through these servers in priority order, lowest number first.
| Priority | Hostname | IP | Status |
|---|---|---|---|
| 10 | inbound-smtp.us-east-1.amazonaws.com | 3.211.210.226 | Reachable |
220 inbound-smtp.us-east-1.amazonaws.com ESMTP Amazon SES UIIgsftd1ci1KOsZBu30No. mail21.cc is a disposable email service. Its mailboxes are throwaway and expire within minutes, so addresses on this domain are not safe to accept or send to. Block it at signup and treat existing mail21.cc accounts as a fraud signal.
Addresses on Mail21.cc are throwaway inboxes that expire within minutes. Accepting them inflates your user count, wastes onboarding spend, and damages sender reputation when the mailboxes bounce.
Each address runs through 30+ checks including SMTP existence, catch-all detection, role-account filtering, and disposable matching. The same engine has verified billions of addresses since 2012.
Every unverified address is a gamble. Here is what happens when you skip verification and mail a list that has not been cleaned.
Disposable signups skew your activation rate, growth metrics, and analytics with users who never come back.
Welcome series and drip campaigns all fire at a mail21.cc inbox that has already been discarded.
Throwaway addresses are the standard tool for free-trial farming, multi-accounting, and bot signups.
Mail to expired mail21.cc inboxes bounces, and bounce rate is one of the first signals mailbox providers punish.
Mail21.cc is disposable email, registered through CSC Corporate Domains, Inc. and first seen Apr 17, 2020.
Mail21.cc is disposable email, classified as disposable email running on amazonaws.com. It operates 1 mail server and currently accepts SMTP connections.
Because mail21.cc is disposable, every address should be blocked at signup. Mailboxes expire within minutes, so any existing mail21.cc account in your database is a strong fraud signal worth removing.
Upload a CSV or TXT list of Mail21.cc addresses to the bulk email verifier. Every address runs through a live SMTP handshake plus catch-all, role-account and disposable detection, and you download a clean list when processing completes. For real-time checks at signup, use the real-time email verification API.
CSV or TXT with one email per line. No formatting needed.
Each Mail21.cc address is checked with a live server handshake.
Get a verified list with status codes, risk flags, and catch-all detection.
Pay as you go. No subscriptions, and credits never expire.
Everything about verifying email at this domain.
While mail21.cc functions as an email domain, it is classified as a disposable or temporary email service. Emails sent to mail21.cc addresses are short-lived and should not be trusted.
Yes, mail21.cc is a known disposable email provider. Addresses on this domain are temporary and should be blocked in registration forms to prevent fake signups.
mail21.cc operates its own temporary mail infrastructure designed for disposable email addresses. Check the MX records section for details.
No, you should not send marketing emails to mail21.cc addresses. Disposable addresses are temporary and will stop functioning. Sending to these domains wastes resources.
While mail21.cc addresses may pass SMTP verification, they should be flagged and rejected. Use BulkEmailChecker disposable domain detection to block mail21.cc automatically.
Upload a CSV or TXT list to the bulk email verifier. Every address runs through 30+ checks including SMTP existence, catch-all detection, role-account, and disposable matching. Processing time depends on list size.
99.7% accurate using a direct SMTP handshake with mail21.cc's mail servers, the same engine that has verified billions of addresses since 2012.
Other disposable email domains we have audited.