InboxGym warms your inboxes, monitors SPF / DKIM / DMARC health daily, and surfaces authentication failures before they cost you a campaign.
No credit card required · Works with any IMAP inbox · Setup in 60 seconds
Why cold email fails silently
Warmup emails exchanged in the wrong language generate weak engagement signals. Inbox providers build your sender profile from that traffic — if the language doesn't match your real campaigns, your deliverability suffers before you send a single cold email.
Warmup emails sent at 3 am target-time look like bot traffic. Inbox providers weight engagement by time-of-day. InboxGym delivers warmup inside business hours for the right timezone.
DMARC aggregate reports tell you exactly which sources are failing authentication. They're sent as XML. Nobody reads them. InboxGym parses them into plain language.
Setup
Paste your IMAP and SMTP credentials. InboxGym validates the connection and verifies DNS records immediately.
Pick a language and timezone that matches your prospects. Warmup traffic will mirror their working hours.
Volume scales up gradually over 30 days. DNS checks run daily. DMARC reports arrive in your dashboard, already parsed.
Live view
sales@acme.com
Inbox placement
Daily sends
Target audience
Pacific Time · Los Angeles
What’s included
From early users
“We lost a domain in Q1 — burned it running cold outreach with no warmup. After InboxGym, we’ve been clean for 8 months across 6 inboxes. The DMARC dashboard caught a broken SPF record I’d have never found manually.”
Marcus R.
Head of Growth, B2B SaaS
“I manage 14 inboxes for clients. The timezone targeting is the thing nobody else offers. Our warmup traffic actually looks like human activity — that’s not nothing when you’re trying to build sender reputation.”
Sophie K.
Founder, cold email agency
The math
Most cold email tools don’t touch DNS or DMARC. That gap has a number.
The decline is gradual until it isn’t. A flagged domain doesn’t recover in a week.
Pricing
First 2 inboxes free. Top up credits when you need more sends — no subscription, ever.
2 inboxes. No expiry.
Unlimited inboxes. Top up when you need it.
1 credit = 1 email sent
Credits never expire. Buy once, use whenever.
Ready when you are
Connect your first inbox in 60 seconds. InboxGym starts monitoring immediately and begins warming up on day one.
Start free2 inboxes included. No credit card.