Donor lists age quickly; re-engagement and sunset policies protect reputation.
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.
Implementation plan for nonprofits#
- 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.
Priorities specific to nonprofits#
Donor lists age quickly; re-engagement and sunset policies protect reputation. Weight your effort toward the steps above that address this constraint first, and measure with metrics that match how nonprofits generate value from email.
Common mistakes#
- Requesting delisting before fixing the cause; repeat listings become harder to remove.
- Ignoring minor blocklists that some corporate gateways still use.
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.