Yes. You can verify any @A1.at address in real time with a direct SMTP handshake that provides 99.7% accuracy. A1.at is operated by A1 Telekom Austria, runs 1 mail server, enforces 3 of 3 authentication standards, and is currently responding to SMTP.
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.
a1.at publishes 1 MX record. The primary mail exchanger is a1-at.mail.protection.outlook.com, hosted by Microsoft 365, 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 | a1-at.mail.protection.outlook.com | 52.101.68.10 | Reachable |
220 DB5PEPF00014B9C.mail.protection.outlook.com Microsoft ESMTP MAIL Service ready at Wed, 3 Jun 2026 20:10:02 +0000 [08DEC0D0BB563C0E]Yes. a1.at is a valid email domain, operated by A1 Telekom Austria. Addresses are persistent and real mail reaches a genuine recipient. Individual mailboxes still go stale, so verify each one before you send.
A live SMTP handshake connects to A1.at's mail server and asks whether the mailbox exists using the RCPT TO command, without ever transmitting a message. The recipient never sees the check.
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.
Free inboxes get abandoned constantly. Verification drops the dead a1.at mailboxes before you mail them.
Mistyped a1.at addresses fail a real SMTP check, so they never turn into a hard bounce.
A clean list keeps your bounce rate low, and a low bounce rate is what protects inbox placement on a big send.
Mailing only live a1.at addresses raises every rate that matters: opens, clicks, and replies.
A1.at is A1 Telekom Austria, registered through A1 Telekom Austria AG ( https://nic.at/registrar/16 ).
a1.at is the email domain for A1 Telekom Austria, the largest telecommunications provider in Austria. A1 offers broadband, mobile, and TV services to millions of Austrian customers, and a1.at email accounts are widely used across the country for personal communication.
A1 Telekom Austria supports SPF authentication on the a1.at domain, and outbound messages generally include DKIM signatures. DMARC policies are published at a baseline level. Senders targeting a1.at addresses should ensure proper SPF alignment and valid DKIM signing to maintain inbox placement.
The a1.at mail servers perform standard recipient verification during the SMTP transaction, rejecting messages for unknown mailboxes with a 550 error. Greylisting may be applied to unfamiliar senders, requiring a retry after a short delay. Rate limiting is enforced for high-volume senders.
When sending to a1.at addresses, maintain clean mailing lists and authenticate all messages with SPF and DKIM. Avoid using purchased lists, as spam complaints from A1 users can quickly lead to blacklisting. Warm up new sending IPs gradually and monitor bounce rates closely.
Upload a CSV or TXT list of A1.at 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 A1.at 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.
Yes, a1.at is a valid and active email domain operated by A1 Telekom Austria, the largest telecom provider in Austria. Email accounts on this domain are used by millions of Austrian residents.
No, a1.at is not a disposable or temporary email service. It is a permanent ISP email domain provided by A1 Telekom Austria to its broadband and mobile customers.
a1.at uses mail servers managed by A1 Telekom Austria infrastructure. The specific MX records point to A1-operated mail gateways that handle inbound email filtering and delivery for all a1.at mailboxes.
You can send marketing emails to a1.at addresses only with proper opt-in consent from the recipients. A1 applies spam filtering, so authenticate with SPF and DKIM, honor unsubscribe requests promptly, and comply with Austrian and EU data protection regulations including GDPR.
You can verify an a1.at email address using an email verification service that checks MX records, performs SMTP mailbox validation, and confirms the address is deliverable. Real-time verification at signup helps prevent invalid addresses from entering your database.
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 a1.at's mail servers, the same engine that has verified billions of addresses since 2012.
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