INBOXSENTINEL

One silent blacklisting costs more than a year of InboxSentinel

Always-on monitoring + human-approved fixes. Cancel anytime.

What a single undetected blacklisting actually costs you
2–4 weeks
replies quietly drop before you even notice
3–6 weeks
to re-warm or rebuy a burned domain
$3k–$5k+
lost pipeline per dead-domain event
$39–$99
to catch it the day it happens, not weeks later
Solo
$39/mo
1–2 domains / up to 3 inboxes
Continuous blocklist + SPF/DKIM/DMARC monitoring · instant blacklist alerts · daily health digest · guided one-click fixes
Start Solo →
MOST POPULAR
Guardian
$99/mo
Up to 10 inboxes / 5 domains
Everything in Solo + priority alerts · per-domain reputation history · multi-domain dashboard · email + Slack/Telegram notifications
Start Guardian →
Fleet
$179/mo
Up to 50 inboxes / 25 domains
Everything in Guardian + Instantly/Smartlead integration · auto-remediation (human-approved safe writes) · cross-customer threat alerts · weekly reporting
Start Fleet →
Agency
$249/mo
Up to 100 inboxes / 50 domains
Everything in Fleet + white-label client reports · multi-workspace · priority remediation SLA · API access
Start Agency →
Cheaper than the warmup tools you already pay for

Guardian works out to $9.90 / inbox / mo — and unlike warmup, it actually tells you the moment a domain gets blacklisted.

Inbox warmup tools
$15–$70 / inbox / mo
warms, but won't alert you to a blacklisting
Manual spam-test tools
$59–$99 / mo
spot-checks only — not 24/7, you must remember to run them
InboxSentinel
from $39 / mo, all inboxes
24/7 watch + instant alert + human-approved fix

14-day money-back · every DNS change is human-approved · we never touch your email content · scans use public DNS + blocklist data only