<b>Blacklist monitoring: catch the burn before it spreads</b>

<b>Blacklist monitoring: catch the burn before it spreads</b>
A single inbox landing on Spamhaus can drag a whole domain. Monitoring is the early-warning system most senders skip.

MXToolbox Delivery Center and GlockApps both watch your sending domains/IPs across major blacklists (Spamhaus, Barracuda, SORBS) and alert on listing. GlockApps adds seed-list inbox placement testing across Gmail/Outlook/Yahoo.

The key cold-email move: monitor per-domain so you can pause and quarantine one burned domain while the rest keep sending.

Pros / Cons
— MXToolbox: broad blacklist coverage, alerts, dated UI
— GlockApps: placement testing + blacklist combo, seed lists can skew vs real inboxes
— Manual checks: free, but you find out too late

Who it's for: anyone running 5+ domains. Below that, a weekly manual Spamhaus check suffices.

Verdict: 4/5 GlockApps for placement + blacklist together, 4/5 MXToolbox for pure list monitoring. The win isn't avoiding a listing — it's isolating the damage in hours, not weeks.