Mailbox MCP vs Nitrosend

A side-by-side comparison built from both listings. Blank cells mean the company has not given that detail; we never guess.

Mailbox MCP compared with Nitrosend
Detail	Mailbox MCP	Nitrosend
What it does	Connect Claude, ChatGPT or any AI to your email mailbox	AI-native email platform for Claude, ChatGPT and any agent
Stage	Established	Startup
Founded	2002	2025
Based in	GB	US
Pricing model	Freemium	Not given
Pricing	Free: 5 calls per mailbox per day, no card required. Pro: £34.99 per mailbox per year plus VAT (£2.92 monthly equivalent). Team Access: Team 3 at £119.99 per year plus VAT, Team 5 at £199.99 per year plus VAT, Team 10 at £399.99 per year plus VAT per account.	Free: $0 (8,000 emails then 500/month). Pro: $20/month (20,000 emails/month). Ultra: $100/month (125,000 emails/month). Enterprise: $300/month (500,000-4,000,000+ emails/month). Extra emails: $0.19 per 100 (Pro), $0.15 per 100 (Ultra). Dedicated IPs: $50/IP/month (Ultra and Enterprise).
Key features	Read email without marking as read Read attachments: PDFs, spreadsheets, photos Reply in thread with proper headers Send as any of your email aliases Email routines on a schedule Permission levels per connection Works with Gmail, Outlook and IMAP	Visual flow builder with event triggers and conditional splits AI-powered content generation with brand voice matching Multi-brand management with isolated sender reputation Unlimited contacts on all plans Dynamic segments and list management with CSV import SMS campaigns via Twilio integration Real-time analytics with AI-powered insights MCP, REST API, SDK, and CLI access on all plans Bring-your-own sending and AI infrastructure keys
What makes it different	Leaves mailbox completely untouched—no duplicate sent items, no marked-as-read flags, threading preserved Works with any MCP-compatible AI—not limited to Claude or ChatGPT Attachments never encoded—up to 20 MB, four ways to attach without passing through AI Email routines run automatically on schedule without manual prompts	Built by email industry veterans with 6 billion emails sent across previous companies AI agents operate email with human approval gates by default Integrated with open-source Email Marketing Bible skill with 908 sources MCP-first architecture with API, SDK and CLI options No per-contact pricing; unlimited contacts on every plan
Free plan	Not given	Not given
Open source	Not given	Not given
Platforms	Not given	Not given
Public API	Not given	Not given
Community votes	0	0
DR (Domain Rating by Ahrefs)	26 +1 (up) since last check	61 +4 (up) since last check
Trust Flow (Majestic)	34	10
Citation Flow (Majestic)	32	32
Referring domains (Majestic)	61	229

7 details filled in for both companies.

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