Legitimate interest is one of the six lawful bases for processing personal data under UK GDPR and the EU regulation. It allows processing, including finding and emailing a person's work address, without consent, provided a three-part test is met and documented: the interest is genuine, the processing is necessary for it, and it does not override the person's rights and expectations. It is the basis most B2B outreach relies on. It never excuses emailing consumers, which in the UK falls under PECR's consent requirement, and it still requires telling the person where you got their address and honouring opt-outs.
The evidence is a legitimate interests assessment: a short written record of the purpose, the necessity, the balancing test and the safeguards (relevance to role, opt-out, minimal data retained, source stated in the first message). It is written once per campaign type, not per contact.
Data quality is one of the safeguards. Keeping only a name, role, company and a verified address, and deleting records that fail verification, is both a balancing-test argument and a deliverability practice. The LinkedIn email finder guide sets out the do and do-not list for found addresses.
A verification vendor emails marketing managers at agencies about bounce rates. The assessment records: interest, selling a relevant tool; necessity, no less intrusive way to reach them; balance, the message concerns their role, states the source, offers one-click opt-out, and the record holds four fields. Addresses that fail verification are deleted rather than retained.
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Verify Leads - FreeAyoub built BounceZero's 5-stage validation pipeline, its dedicated BGP-announced IP infrastructure, and the Patroni HA PostgreSQL cluster behind every verification. Previously built high-volume email delivery infrastructure. Trained at 1337 Benguerir (École 42 network, 2019). Open-source: bgp_analyzer.