| Onet | |
|---|---|
| Domains | onet.pl, op.pl, poczta.onet.pl, vp.pl |
| Mail routing | Onet-operated hosts serving the onet.pl family, under Ringier Axel Springer's Polish operation. |
| What we can resolve | We resolve most mailboxes here |
How Onet answers a probe
What the server does when we open a connection and ask about one address.
- Unknown recipients return a 550 consistently.
- The poczta.onet.pl form is a full domain in its own right, not a subdomain trick, and addresses on it are common.
- Rate limits are workable and enforcement is predictable.
- The op.pl and vp.pl domains are shorter brand variants on the same service.
The part that catches people out
What we do about it
We verify each Onet domain form independently, because they genuinely are independent mailboxes. Merging them would be a convenient assumption rather than a measured fact.
Sending to Onet mailboxes
Verification is one step. These are the things that decide whether the message lands.
- Onet and WP.pl together cover most Polish consumer email outside Gmail.
- Polish-language content performs measurably better with this audience than English does.
- Watch for the same name across the domain variants when judging list size.
buziaczek.pl is a real mailbox
Say you're cleaning a Polish contest list by eye and you hit kasia@buziaczek.pl, then someone at amorki.pl, then autograf.pl and spoko.pl. They read like joke domains (buziaczek means a little kiss), and a careful human deletes them as fake signups. Don't. Onet has offered all of them as address choices for years. On September 19, 2026 each one returned mx.poczta.onet.pl, the same single host that answers for onet.pl, op.pl, vp.pl, onet.eu and onet.com.pl.
Those rows get the same direct answer at RCPT TO as any other Onet mailbox, so let the server decide. The general lesson for any list is cheap to apply: before removing a domain because it looks silly, look up its MX. A novelty name pointing at a major provider's host is a customer with a sense of humor.
Counting people when one provider has ten domains
The flip side of all those domain choices is that one name can exist many times. jan.nowak could be registered at onet.pl by one person and at op.pl by another, or the same Jan might have opened both over the years. The server can't tell you which, and a verifier shouldn't pretend to.
What you can do is use the data you already hold. If two Onet-family rows share a local part and also share a postal code, a phone number or an order history, merge them and keep the one that clicked most recently. When they share only the local part, leave them alone. For reporting, give the client two numbers: addresses verified and probable unique people. On a Polish consumer list the second figure can be noticeably smaller, and it's the one that should drive their cost-per-customer math.
Questions people ask
Is poczta.onet.pl a real domain?
Yes. It has its own MX records and its own mailboxes. An address there is not the same mailbox as the equivalent local part at onet.pl.
How verifiable is Onet?
Well. Clean rejections, reasonable limits, no accept-all policy standing in the way.
Should Onet and WP.pl be treated together?
Segment them. They are separate companies with separate filtering behavior, and their audiences differ in age and habits.