AI-powered email warmup tool that improves inbox placement and sender reputation
Newsletter sponsorship platform connecting brands with publishers
Stage
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Founded
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Based in
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Pricing model
Freemium
Freemium
Pricing
Free Forever plan with 1 mailbox and 10 warmup emails per day. Basic plan $49/month for 5 mailboxes and 150 warmup emails per day. Growth plan $99/month for 20 mailboxes and 300 warmup emails per day. Premium plan $189/month for 40 mailboxes and 500 warmup emails per day. Yearly billing discounts av
Free to join for both brands and newsletters. Brands pay the sponsorship price only after a newsletter accepts. LetterBid keeps 25% of each sponsorship as fee (includes payment processing); newsletters receive 75%.
Key features
Automated inbox warming with 40,000+ real inboxes
AI Read Emulation for human-like engagement patterns
Real-time email health monitoring and analytics
100+ blacklist scanning and monitoring
Auto-archive of warmup replies
Support for 30+ languages
Integration with Gmail, Outlook, SMTP, SendGrid, Mailgun, Amazon SES
Specific topic warmup selection
Multiple mailbox support
14-day money-back guarantee
Newsletter discovery with verified audience data
Three sponsorship placement types: dedicated email, sponsored ad, banner ad
Direct, multi-newsletter, and recurring campaign types
Custom offer negotiation with up to 3 counter offers
Payment held in escrow until delivery approval
Verified newsletter badges with audience verification
Delivery reports and brand approval process
Public storefront for newsletters with shareable booking link
Stripe integration for payouts on the 15th of each month
Dispute resolution with LetterBid team intervention
What makes it different
Setup in 30 seconds with no technical configuration required
98% inbox placement rate across major email providers
Real people, real mailboxes with authentic engagement signals
Comprehensive email health monitoring with DNS and authentication checks
Free Forever plan with no credit card required
Transparent, fixed pricing with no hidden fees or surprise charges
Payment held in escrow and released only after delivery proof and brand approval
Verified audience data for newsletters to reduce guesswork
No upfront payment required; brands pay only after newsletter acceptance
Dispute resolution system with fair split option if sides cannot agree
E-Warmup
LetterBid