Email domain
aon.at email servers, SPF and DMARC
Mail for @aon.at goes to smx01.a1.net (MX priority 10), as DNS showed on 5 November 2026. The host sits under a1.net. The domain publishes an SPF record ending in -all and a DMARC policy of p=reject, which decide whether mail claiming to be from @aon.at is trusted.
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aon.at mail DNS on 5 November 2026
| Priority | MX host | Platform |
|---|---|---|
| 10 | smx01.a1.net | Not identified |
| SPF | v=spf1 include:aspf.a1.net -all |
|---|---|
| DMARC | v=DMARC1; p=reject; rua=mailto:[email protected] |
| MTA-STS | None published |
| TLS reporting | None published |
Read on 5 November 2026 with dig against 1.1.1.1 (8.8.8.8 as fallback); nothing sent to the mail servers. Check the records today with the email provider lookup.
aon.at MX records
aon.at publishes a single MX host, smx01.a1.net. With no backup host, a sender that can't reach it queues the message and retries until the server answers or the queue gives up.
1 other domain we checked on the same day also route mail to hosts under a1.net, with different records from aon.at: a1.net.
aon.at SPF record
The record on 5 November 2026 was v=spf1 include:aspf.a1.net -all.
In plain terms, it delegates to aspf.a1.net. The top level uses 1 DNS-querying term; SPF allows 10 in total including nested includes (RFC 7208 §4.6.4).
It ends in a hard fail (-all): receivers may reject mail from any server the record does not list.
aon.at DMARC policy
The record is v=DMARC1; p=reject; rua=mailto:[email protected].
p=reject asks receivers to refuse mail that fails DMARC.
Aggregate reports go to a1.net, so the domain's owner sees who sends mail as @aon.at.
What that means for you: if a contact gives an @aon.at address and you send to them, nothing changes. But never put an @aon.at address in the From line of mail sent through your own tool or ESP. It can't pass DMARC for aon.at, and this policy tells receivers to refuse it.
Can you verify @aon.at addresses?
Our checker treats @aon.at like any domain: syntax, MX, disposable and role checks first, then a made-up address to rule out a catch-all, then your address at RCPT TO, disconnecting without sending. We have not published a test of how smx01.a1.net answers for @aon.at, so we make no claim here about whether single mailboxes can be confirmed; each result carries its own reason.
Cleaning a list with these addresses
DNS tells you where mail goes, not whether one person's mailbox still exists. For a list, run the whole file through a verifier before you send: invalid rows come out, risky rows (catch-all, unknown, refused) go in their own segment, and valid rows are safe to mail.
Common questions
- What are the MX records for aon.at?
- On 5 November 2026:
smx01.a1.net(priority 10). - Does aon.at have SPF and DMARC?
- On 5 November 2026
aon.atpublished an SPF record ending in-alland a DMARC policy ofp=reject. - Is aon.at a disposable email domain?
- No.
aon.atis not on the disposable domain list our checker uses, so @aon.at addresses are checked like any other mailbox. See the disposable domain checker for the list.
Free checks for @aon.at lists
- Bulk email checker for a pasted list or CSV
- Verify a whole file with a reason for every row
- SPF lookup counter
- MTA-STS checker
- Disposable email checker
Another domain? See every email domain we have mapped and what our checker does at each mailbox provider.
Got a list with @aon.at addresses?
Sign in with Google and the first 100 addresses are checked free: valid, risky and invalid, with the reason for each row and a file to download. No card. After that, plans start at $9/mo for 2,500 emails a month.
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