Open Beta · free for the first two months - then pricing applies

Don't let your work
get unseen.
Warmup and get more opens.

WarmupSleuth quietly builds the sender reputation of your inbox — no work required on your end. Connect a mailbox and let Warmup Sleuth do the magic, so your real emails land in the inbox.

GDPR-native · EU-hosted · no credit card to start

inbox · placement monitor
mark_email_readQuarterly product update — to a Gmail recipientInbox
mark_email_readRe: intro & next steps — to a Microsoft 365 recipientInbox
mark_email_readFollowing up on your request — to a custom-domain recipientInbox
Open
Beta — free now
9+
ESP connectors
GDPR
Native by design
EU
Data residency
Built for everyone

A powerful tool that helps your work get visible.

We all know the hassle — hundreds of emails end up in spam every month and your prospects never see your offer. WarmupSleuth is here to fix it. Geeks or non-coders, everyone can improve their sender reputation.

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Major ESP connections

Integrations for Google Workspace and Microsoft 365 inboxes, with SMTP/IMAP fallback for custom inboxes.

insights

Segmented reputation

Separate scores for Google, Microsoft and Other inboxes. Spot divergence early — before one bucket tanks while others stay green.

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Fine-tuned content generated by AI

Our warmup emails use simple text formatting — no redundant links, attachments or spam triggers. Not templates that ESPs catch in seconds.

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Custom ramp & schedule

Pick a ramp curve, set business hours and topics. The schedule respects your timezone and eases off on weekends.

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EU-hosted, GDPR-native

Hosted in the EU with privacy built in. Right-to-export and right-to-delete out of the box — no add-ons, no surprises.

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Beta version explained

While we bring our network to full performance, we're in open Beta — planned for about two months. When it ends, you can go paid or leave the warmup environment.

How it works

Two minutes to your first warm send.

Connect a mailbox, optionally drop in a template, and the warmup loop runs the rest. Your sender reputation accumulates over time.

01

Connect a mailbox

Gmail, Microsoft 365, or any SMTP+IMAP provider. OAuth or app password — your call. Domain detection pre-fills the host and port.

02

Pick a ramp

The standard ramp covers most accounts. Draw your own curve if you've already started warming elsewhere.

03

Watch the score build

Your reputation starts building within ~24 hours. The donut and per-ESP grid populate from there, and drift gets flagged early.

Ready to make your real sends land?

Connect a mailbox in two minutes and watch reputation build. Free for the first two Beta months.

play_arrow Start free Beta