# Contact data guides and explainers — Ravn

Canonical: https://askravn.com/blog

Blog

# How contact data works, explained plainly.

Short, practical guides to the mechanics behind contact data: how an address gets checked, why some can never be confirmed, and which rules apply when you reach out.
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## Blog
These guides explain the plumbing behind the tools: DNS and SMTP, address patterns, bounces, hashing and the laws that govern outreach. They are written for people who send email, build lead lists or wire agents up to data, and they say plainly where a check stops being certain.When a guide mentions Ravn, it links to the page with the details. You can try the checks yourself with the free [email verifier](https://askravn.com/tools/email-verifier) and [email finder](https://askravn.com/tools/email-finder), or look up terms in the [glossary](https://askravn.com/glossary).
- [B2B contact data compliance basicsCAN-SPAM, CASL, GDPR, CCPA/CPRA, data broker rules and FCRA limits explained in plain language for teams that use B2B contact data..](https://askravn.com/blog/b2b-contact-data-compliance)
- [Connect Claude to contact data with MCPMCP lets Claude call outside tools.](https://askravn.com/blog/connect-claude-to-contact-data-mcp)
- [Email bounce rate: a practical guideWhat hard and soft bounces are, why they damage sender reputation, and a simple clean-before-send routine that keeps your bounce rate down..](https://askravn.com/blog/email-bounce-rate-guide)
- [Hashed email audiences explainedHow SHA-256 hashed customer lists work for Meta and Google, the normalisation rules, why hashing is not anonymisation, and how to build one locally..](https://askravn.com/blog/hashed-email-audiences-explained)
- [How email finders workEmail finders guess addresses from a name and company using known patterns like first.last, then verify each guess.](https://askravn.com/blog/how-email-finders-work)
- [How email verification worksEmail verification checks syntax, DNS and MX records, then asks the mail server about the mailbox without sending.](https://askravn.com/blog/how-email-verification-works)
- [What is a catch-all email domain?A catch-all domain accepts mail for any address, real or not, so no verifier can prove a mailbox exists there.](https://askravn.com/blog/what-is-a-catch-all-email-domain)