Poland is one of the last large European markets where the domestic portals still hold meaningful consumer mail share. WP.pl (Wirtualna Polska) and Onet.pl predate Gmail by years and their webmail products still sit on millions of home screens. If you are running Polish B2C, you cannot skip them.
GlockApps and most mainstream placement tools do not seed WP.pl, Onet.pl, o2.pl or Interia.pl. The Polish filter behaviour is invisible to them. This is the single biggest gap for senders into Central Europe — and the one we built our tool to close.
The Polish ISP landscape
A realistic snapshot of Polish consumer mailboxes:
- WP.pl — the Wirtualna Polska portal's mail. Also
wp.pl,o2.pl,pudelek.pl,tlen.pl— these are all run on the same infrastructure after a series of acquisitions. - Onet.pl — portal mail run by Ringier Axel Springer. The other historical heavyweight.
- Interia.pl — smaller but non-trivial, often the third or fourth inbox on a Polish consumer list.
- Gmail — dominant among under-35 urban users.
- Outlook, Yahoo — present but secondary.
On a typical Polish B2C list WP.pl plus Onet.pl plus the smaller local providers adds up to 35–55% of recipients. On older, more rural, or more institutional lists it can be more than half.
WP.pl: strict DKIM, strict content
WP.pl's filter is one of the strictest in Europe on authentication. The rule of thumb we see in thousands of tests: no DKIM, no inbox. Not "DKIM is a soft signal" — missing DKIM is a near-guaranteed spam placement on WP.pl even if SPF is clean.
Content filtering is aggressive too. WP.pl runs local rules tuned to Polish-language spam that Western Bayesian filters have never seen: certain loan-offer phrasings, certain adult-site URL patterns, and a long list of Polish-language marketing templates known from past abuse. A message that clears SpamAssassin cleanly in English may hit specific WP.pl rules in Polish.
WP.pl postmaster portal
WP.pl runs a postmaster portal at postmaster.wp.pl. It offers domain registration, a feedback loop, and a delisting form. Like Google Postmaster Tools, it needs DNS verification. Unlike Google, it is in Polish — Chrome translate is your friend. If you send any meaningful volume to WP.pl, registration is non-optional.
Onet.pl: similar strictness, different signals
Onet.pl's filter weights engagement more heavily than WP.pl does. This works for you if you have an engaged list and against you if you are cold. Onet.pl is also more sensitive to link count — more than a handful of tracked links in a short message elevates the score fast.
Onet.pl does not publish a postmaster portal with the same maturity as WP.pl. If you are blocked, the only channel is a general abuse contact and response is slow.
Local blacklists: Surbl.pl and company
WP.pl, Onet.pl and the smaller Polish providers all consult the domestic RBL Surbl.pl in addition to the international Spamhaus and SURBL services. Surbl.pl's listings focus on Polish-facing phishing and local spam runs and are invisible to senders who only monitor the international blacklists.
Before sending to a Polish list, query your sending IP and your linked domains against surbl.pl. If you are listed there without being listed anywhere else, you have a local-only reputation problem and you should solve it before the send.
UTF-8 and Polish characters
Polish uses diacritics — ą, ć, ę, ł, ń, ó, ś, ź, ż — and they appear everywhere: names, places, subject lines, unsubscribe copy. If your sending pipeline loses or mangles them, the mail looks like a poorly localised spam attempt, which is exactly what filters are trained to catch.
- Encode every message as UTF-8 end to end.
Content-Type: text/plain; charset=UTF-8andContent-Transfer-Encoding: quoted-printableorbase64for any body containing Polish characters. - Subject lines with diacritics need MIME encoded-word syntax:
=?UTF-8?B?...?=or=?UTF-8?Q?...?=. - Verify with a test to WP.pl — not Gmail. Gmail is very forgiving of sloppy encoding. WP.pl is not.
How cold sequences typically get flagged
In our placement data, Polish cold email gets flagged in the same five ways over and over:
- English template sent to Polish addresses. Filter sees language mismatch plus bulk pattern and scores it as spam before content rules even run.
- Machine-translated Polish. The phrase "I hope you are doing well" in literal Polish translation matches known spam signatures.
- Missing DKIM. Kills WP.pl. Full stop.
- Shared IP with past Polish complaints. Lookup on postmaster.wp.pl tells you instantly.
- Tracking domains on a cheap TLD (
.click,.top,.xyz). Polish filters treat them as presumptively suspicious.
Before any Polish send: (1) DKIM signing verified against wp.pl and onet.pl seeds, (2) message localised by a human, not a machine, (3) tracking domain on .pl or a well-aged .com, (4) surbl.pl check clean, (5) a placement test showing inbox on both WP.pl and Onet.pl.
Free placement testing for Polish ISPs
Our placement tool seeds WP.pl, Onet.pl, Interia.pl and o2.pl alongside the usual Gmail / Outlook / Yahoo set — plus 15 more European, privacy and CIS providers. Send one test email, get per-provider inbox / spam / missing back with raw headers. Free, unlimited, no signup. It is the simplest way to catch a Polish-specific filter problem before it costs you a campaign.