What CASL requires#
CASL requires express or implied consent before sending and identification of the sender in every message.
What email blocklists are#
Blocklists (Spamhaus, SpamCop, Barracuda, and others) publish IPs and domains observed sending spam. Receivers query them at connection time to reject or filter mail.
Why it matters#
A Spamhaus SBL or DBL listing can block delivery to a large share of the internet within hours.
How email blocklists supports CASL compliance#
Regulators and recipients need to identify who sent a message and trust that opt-out mechanisms work. Email blocklists contributes by a Spamhaus SBL or DBL listing can block delivery to a large share of the internet within hours.
Implementation steps#
- Check your IPs and domains against major blocklists weekly.
- Identify the cause: compromised account, list purchase, spam trap hits, or a misconfigured forwarder.
- Fix the root cause and document what changed.
- Submit a delisting request through the blocklist's process with evidence of remediation.
- Monitor for relisting for 30 days.
Frequently asked questions#
How long does Spamhaus delisting take?
Often within hours for SBL and CSS if the cause is fixed. DBL domain listings can take longer.
Which blocklists matter most?
Spamhaus (SBL, XBL, DBL), SpamCop, Barracuda, and SURBL have the widest impact.