Short version: SURBL has no impact on deliverability in 2026. If your domains show up on SURBL, there is no need to panic, pause campaigns, reduce volume, or change anything — keep warming up and keep sending as usual.
Why a SURBL listing is not a problem
Google has effectively stopped paying attention to SURBL, largely because it began flagging far too aggressively over the past year — to the point of affecting paid Google/Microsoft enterprise infrastructure and legitimate businesses. As a result, major mailbox providers place little to no weight on SURBL today.
A real example from our own accounts: one client had 188 domains listed on SURBL and kept sending cold email throughout. Their reply rate did not change at all, and we continued to see solid spam-test results from those same listed domains.
A few important technical points:
SURBL lists the domain (URL reputation), not your sending IP.
Our sending IPs are not blacklisted — they stay green, and we rotate IPs automatically.
A SURBL "multi" listing in tools like MXToolbox or an Instantly warning ("contains a URL listed in the ABUSE SURBL blocklist") can be safely ignored; it does not reflect inbox placement.
What you should do
Keep warming up your mailboxes.
Keep your campaigns running as usual — no need to pause, slow down, or change settings.
Do not delete mailboxes or domains in reaction to a SURBL listing.
Reference image: https://ibb.co/gLZjKKxt
Not the same as a registrar suspension
A SURBL listing is very different from a registrar/registry suspension, which is a hard block that stops a domain from resolving or sending until it is reinstated. If a domain is actually suspended (rather than just SURBL-listed), contact support to confirm the status and discuss options such as a replacement domain.
Other deliverability questions
For deliverability topics beyond SURBL — inbox placement or spam diagnosis, warmup-flag issues, blacklist delisting requests, or "why are my results low" — please contact support so our deliverability specialist can review your specific account. You can also book a deliverability audit from the top-right option after logging in.