Apollo.io vs MailProbe
Apollo.io is a plugin bundle for AI coding tools published by Apollo.io. Marketplaces we read that list it: 1 (Claude: knowledge-work-plugins). MailProbe is an MCP server published by mailprobe.dev. Marketplaces we read that list it: 1 (Official MCP Registry). As of our marketplace pass on 2026-10-15. This pair was picked by a reader, not by our comparison rule, so search engines are asked not to index the page.
Where each is published
| Marketplace |  MailProbe | |
|---|---|---|
| Claude: knowledge-work-plugins | Listed Version: 0.1.0 Forks (GitHub): 3 361 Stars (GitHub): 29 647 Not marked · First seen |
Not listed |
| Official MCP Registry | Not listed | Listed Version: 1.1.1 Downloads/month (npm): 668 Downloads/week (npm): 668 Forks (GitHub): 0 Stars (GitHub): 0 Not marked · First seen |
Each figure is the marketplace's own and is never added up across marketplaces. A marketplace that publishes no figure shows none: no number is not zero.
The facts side by side
| Fact | Apollo.io | MailProbe |
|---|---|---|
| Marketplaces that list it | 1 | 1 |
| Stars (GitHub) (differs) | 29 647 (better) | 0 (worse) |
| Forks (GitHub) (differs) | 3 361 (better) | 0 (worse) |
| Last release | Not published | Not published |
| Where it runs (differs) | Remote server (mcp.apollo.io/mcp) | Remote server (mailprobe.dev/mcp) |
| Transport | Streamable HTTP | Streamable HTTP |
| Tools it declares | Not published | Not published |
| Environment variables it asks for (differs) | Not published | 1, secrets among them: 1 |
| Parts of the bundle (differs) | 4 | Not a bundle |
| Licence (differs) | MIT | Not stated |
| Repository (differs) | github.com/anthropics/knowledge-work-plugins | github.com/jamalofski/mailprobe-mcp |
| Changes in the last 7 days | 0 | 0 |
| First seen | 2026-10-11 | 2026-10-11 |
| Endpoint at the last check (differs) | Responded 26 h ago | Not responding since 2026-10-14 |
Lines where the two differ have a tinted background and bold values. Where the data itself says which value is better (more marketplaces, a larger figure of the same marketplace, a fresher release, a verified mark on a marketplace that lists both), the better one is also marked green with ▲ and the worse one red with ▼. Where it runs, the transport, the tools, the settings, hooks, the bundle's parts, the licence and the week's changes are marked only as different: more or fewer is not better in itself.
What each says it does
Apollo.io
Prospect, enrich leads, and load outreach sequences with Apollo.io — one-click MCP server integration for Claude Code and Cowork.
MailProbe
Verify email addresses in real time: deliverability, disposable and role addresses, typo fixes.
How to run each
Apollo.io As a Claude Code plugin
/plugin marketplace add anthropics/knowledge-work-plugins
/plugin install apollo@knowledge-work-pluginsMailProbe As a remote MCP server
claude mcp add --transport http mailprobe https://mailprobe.dev/mcp --header "Authorization: Bearer <YOUR_API_KEY>"Requires: MAILPROBE_API_KEY (secret), Authorization header
Commands built only from what the marketplaces declare; the full set for every client is on each card.
Only the endpoint of Apollo.io responded at the last daily check. How we check endpoints
Tools each declares
Neither one's marketplaces publish a list of tools, so there is nothing to compare.
Settings each asks for
The marketplaces of Apollo.io publish no settings it asks for, so we do not compare settings.
What it can do: Apollo.io · What it can do: MailProbe · Compare two other plugins
Data comes from the public marketplace file https://github.com/anthropics/knowledge-work-plugins/blob/HEAD/.claude-plugin/marketplace.json. Data comes from the Official MCP Registry (registry.modelcontextprotocol.io), CC0 1.0. Figures come from our own regular passes over the marketplaces, last read on . We publish no contact details for plugin publishers.