This blocklist is no longer operational. DNS queries return NXDOMAIN. Remove from MTA configurations to avoid query timeouts.
What it is
Woody.ch operated a small SMTP-oriented blocklist covering spam sources. It was a niche, independently maintained list with limited deployment. The project has been discontinued.
How it affects SMTP delivery
No impact. Remove from MTA configurations to avoid DNS timeout overhead.
What causes a listing
N/A, defunct.
How to get removed
No removal necessary.
For the full reference catalog, see the email blocklist directory.
Delisting process in detail
The Woody SMTP blocklist (blackholes.woody.ch) is operated by the same team as Nether and other Swiss-based lists. Delisting is handled through the operator’s contact form. Response times are typically within 24-72 hours for well-documented requests. Automatic decay applies when the observed spam pattern stops. The blocklist focuses on SMTP-level abuse patterns rather than general spam observation.
Prevention practices
Woody SMTP prevention focuses on SMTP hygiene: proper HELO/EHLO configuration, valid reverse DNS with forward-confirmed matching, no open relaying, and prompt rejection of invalid recipients at RCPT TO time (not accept-then-bounce). Authentication (SPF, DKIM, DMARC) matters as elsewhere, but the SMTP-level configuration is particularly important for avoiding Woody SMTP listings. Sending servers should present a consistent identity across HELO, reverse DNS, forward DNS, and DKIM signature domain.
Common listing causes
Woody SMTP listings often stem from SMTP misconfiguration rather than raw spam volume: mismatched HELO and reverse DNS, missing PTR records, HELO strings that do not resolve, or open-relay behavior on the sending server. Compromised mail servers being used as open relays are particularly likely to trigger Woody SMTP listings. For legitimate senders, careful MTA configuration and monitoring for open-relay conditions are the primary defenses.
Related blocklists
SMTP-hygiene focused blocklists include Woody SMTP, Backscatterer (also from the same team), and various regional lists that check MTA configuration alongside spam observation. Enterprise mail administrators should verify SMTP configuration against best practices (HELO matches PTR, PTR is forward-confirmed, no open relay, no accept-then-bounce). These practices prevent Woody SMTP listings and improve general deliverability at strict receivers.
About the Author
Alaa · LinkedIn
Email infrastructure specialist with 8+ years of hands-on experience in SMTP, deliverability, and email verification. I’ve configured and troubleshot mail systems across Postfix, Exchange, and cloud relays, managed IP reputation and warmup campaigns, and built verification pipelines processing millions of addresses. My work spans DNS authentication (SPF, DKIM, DMARC, BIMI), bounce handling, blocklist monitoring, and compliance frameworks including CAN-SPAM and GDPR. I write every article on SMTPedia to give email professionals, developers, and marketers the accurate, RFC-grounded reference they need.
About SMTPedia
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