A side-by-side look at the Oldweb Diagnostics and Mail7 Email Validation MCP servers: transport, auth, tools, quality signals, and the config to install either one in Claude, Cursor, Windsurf or VS Code.
Verdict: choose Oldweb Diagnostics for communication work; choose Mail7 Email Validation for communication as a local process. You can also run both side by side in one mcpServers block.
MAIL7_API_KEY, MAIL7_BASE_URL.validate_email, validate_emails, check_domain.Rows where the two servers differ are marked.
| Spec | O Oldweb Diagnostics | |
|---|---|---|
| Category | Communication | Communication |
| Quality signal | 36/100 · Fair | 56/100 · Good |
| Install command | Not confirmed yet | Confirmed |
| Transport | — | Local subprocess (stdio) |
| Auth | No auth required | Not declared |
| Pricing | Free | Not declared |
| Required env vars | None listed | MAIL7_API_KEYMAIL7_BASE_URL |
| Verified owner | Community listing | Community listing |
| GitHub stars | 0 | 0 |
| Directory activity | 0 views 0 installs 0 upvotes | 2 views 0 installs 0 upvotes |
| Tools | Not listed | 4 |
| Full listing | View Oldweb Diagnostics | View Mail7 Email Validation |
No tool names declared yet. Check the project README from the listing page.
validate_emailCheck whether a single email address is deliverable: syntax, domain MX records, disposable-domain database and a live SMTP mailbox probe. Status is one of "Valid", "Not Valid", "Unknown". Unknown means the mailbox could NOT be checked (catch-all domain, greylisting, blocked SMTP port) - it is NOT a bad address. Never delete, reject or report Unknown addresses as invalid; present them separately and let the user decide. Use validate_emails instead when you have more than one address.validate_emailsCheck up to 50 email addresses in one call and get a per-address verdict plus a summary. Status is one of "Valid", "Not Valid", "Unknown". Unknown means the mailbox could NOT be checked (catch-all domain, greylisting, blocked SMTP port) - it is NOT a bad address. Never delete, reject or report Unknown addresses as invalid; present them separately and let the user decide. Requires MAIL7_API_KEY (anonymous callers get a 25-address free sample only). Each address takes a few seconds of real SMTP work, so this call is slow by nature: for a longer list, split it and call this tool repeatedly with the next 50 addresses. Never run two calls in parallel - the API serialises one bulk job per client and the second call fails.check_domainAudit a domain's email setup in one call: MX records, SPF, DKIM, DMARC, MTA-STS, TLS-RPT, DNSSEC and BIMI, graded A-F with a fix for every problem found. Use this to answer "can this domain send and receive mail" or "why do our messages land in spam". Takes a domain (example.com), not an email address. The default answer summarises every section; pass `section` to get the full records and findings of one of them.check_spfFetch and analyse the SPF record of a domain: the raw record, its mechanisms, lookup count and common misconfigurations. Use check_domain instead when the question is about overall deliverability rather than SPF specifically.Paste either block (or both) into your client config, e.g. claude_desktop_config.json or ~/.cursor/mcp.json. We only show a config when the install command is confirmed.
No confirmed install command for Oldweb Diagnostics yet — follow the setup steps linked from its listing page rather than a guessed package name.
{
"mcpServers": {
"mail7-email-validation": {
"command": "npx",
"args": [
"-y",
"mail7-mcp"
],
"env": {
"MAIL7_API_KEY": "YOUR_MAIL7_API_KEY_HERE",
"MAIL7_BASE_URL": "YOUR_MAIL7_BASE_URL_HERE"
}
}
}
}