SparkGPT vs Mailbox MCP

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

SparkGPT compared with Mailbox MCP
Detail	SparkGPT	Mailbox MCP
What it does	AI sales agent that turns website visitors into buyers	Connect Claude, ChatGPT or any AI to your email mailbox
Stage	Not given	Established
Founded	Not given	2002
Based in	Not given	GB
Pricing model	Freemium	Freemium
Pricing	Free Plan: $0 forever. Build and test one agent with unlimited testing, no credit card required. Growth Plan: $49/month plus 5% of attributed sales, with unlimited conversations and full ROI dashboard. Done For You: custom 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.
Key features	Paste website URL and agent is built automatically from site content Claude-powered AI with intelligent model routing Product recommendation engine Sales attribution tracking with 24-hour window ROI dashboard showing every attributed sale Single line of code deployment Works with Shopify, WordPress, and custom sites Unlimited conversations on Growth plan Prepaid credit billing model Built for small and mid-sized online businesses	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
What makes it different	Outcome-based pricing tied to attributed sales, not conversation volume No credit card required to build and test for free forever No technical setup required; built from your existing website content Transparent ROI with every attributed sale visible and inspectable Built on Anthropic's Claude for stronger reasoning and sales capability	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
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)	43 no change since last check	37 −1 (down) since last check
Trust Flow (Majestic)	9	34
Citation Flow (Majestic)	19	32
Referring domains (Majestic)	28	61

5 details filled in for both companies.

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