Email deliverability guides
Is your email blacklisted? Verify it before you act.
A bounce message or a sudden delivery problem does not prove a blacklist listing. Start by confirming which list, if any, actually lists your domain or IP — and whether that list matters to the providers you send to.
Published by InboxGenius
What a blacklist listing actually means
Blocklists are one signal among many
DNS-based blocklists publish IP addresses or domains that some receiving systems consult. A listing on one list does not mean every provider blocks your mail, and absence from every list does not prove inbox placement. Treat a listing as one confirmed fact, not a complete diagnosis.
A listing names a specific resource
Blocklists list an IP address or a domain, not your email platform as a whole. Identify exactly which resource is listed — your dedicated outbound IP, a shared platform IP, or your sending domain — because the investigation and the fix differ for each.
The bounce message is your evidence
When a rejection cites a blocklist, the SMTP response usually names it. Keep the full response text; a generic “blocked” message without a list name points to a different investigation. Our guide to SMTP delays and rejections explains how to read those responses.
Confirm the listing with evidence
Check the list’s own lookup
Most public blocklists operate a lookup tool. Query the exact IP address or domain the bounce message named, and record the listing reason and timestamp the list publishes. A screenshot or saved response is more useful than a remembered result.
Check the domain as well as the IP
Domain-based and URI blocklists list sending domains or links inside messages. An IP-only lookup can miss a domain listing entirely, so verify both resources named in the evidence you collected.
Compare with provider-level signals
For mail sent to personal Gmail accounts, review the available Postmaster Tools dashboards. A listing may affect one receiving network and be ignored by another, so compare the listing with what each provider’s own evidence shows.
Questions worth asking before requesting removal
Does a listing explain every failure?
No. Receiving networks weigh many signals, and providers rarely publish which lists they consult. If some messages still arrive while others fail, look for the additional evidence before attributing everything to one list.
Should we request delisting immediately?
Removal without correcting the underlying cause often leads to re-listing, sometimes with a longer penalty window. First establish why the resource was listed — the list’s published reason is the starting point — and address that cause before asking for removal.
When is specialist support useful?
Bring in support when the listing recurs, several teams own different pieces of the sending environment, or the evidence is difficult to reconcile. InboxGenius provides email deliverability consulting through an ongoing monthly retainer. We do not guarantee placement or sell hourly consulting. For recurring issues across teams or platforms, consider ongoing managed postmaster support.
Confirm the listing. Then decide what to do about it.
Tell us which list your bounce messages name, your sending platforms, and when the problems began. Keep passwords, API keys, and recipient lists out of the inquiry form.