A free, no-login remote MCP server for email deliverability: verify addresses, audit SPF/DKIM/DMARC, explain SMTP errors, and build SPF and DMARC records.
What you can do
Verify a single email address for format, typo suggestions, disposable or shared mailboxes, and whether the domain accepts mail, returning valid, risky or invalid with a did_you_mean hint. Audit a domain's email setup: SPF, DKIM selectors, DMARC, MX and provider, MTA-STS, TLS-RPT and BIMI, with a 0 to 100 score, grade and plain-language fixes. Explain bounce or SMTP error text as hard, soft or policy, naming the provider and next step. Generate an SPF record from the services that send for a domain, starting with softfail. Generate a DMARC record with a starting policy and report address.
When to use it
Useful when checking whether an address is worth sending to, diagnosing why mail from a domain lands in spam or fails authentication, interpreting a bounce message, or drafting SPF and DMARC records before publishing them.
Requirements
A remote streamable HTTP endpoint; no login, API key, environment variables or headers are declared. The verification and DNS checks need network access to look up the queried domains.
Before you install
The checks are read-only and the record generators only produce text, but the generated SPF and DMARC records must be reviewed and published by you in DNS. Addresses and domains you submit are sent to the third-party service at the remote endpoint.
Enable the server for the chats that should use its tools.
Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.
Use with an agent
Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.
Read https://sourceweft.com/mcp/com.couryo%2Ftools/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.
Checks one email address without sending anything: format, typo in big providers ("gmail.com.br" → "gmail.com", "hotmial.com"), disposable inbox, shared mailbox (contato@, sales@) and whether the domain receives email (MX). Verdict valid, risky or invalid, with did_you_mean. The mailbox itself is never probed. Free, read only. / Confere um endereço sem enviar nada: formato, erro de digitação, e-mail temporário, caixa compartilhada e se o domínio recebe e-mail.
Parametersemailrequired
check_domain_dns
Check a domain's email DNS / Verificar SPF, DKIM e DMARC
Checks the email setup of any domain: SPF (one record, ending, the 10 DNS lookup limit), DKIM on the common selectors (or dkim_selector), DMARC policy and reports, MX and mailbox provider, MTA-STS, TLS-RPT and BIMI. Answers a 0 to 100 score, a grade, the fix for each problem in plain words and records ready to copy. Free, read only. / Confere SPF, DKIM, DMARC e MX de qualquer domínio, com nota e a correção de cada problema.
Parametersdomainrequireddkim_selector
explain_smtp_error
Explain an SMTP error / Explicar erro de e-mail
Explains a bounce or SMTP error text ("550 5.7.515 Access denied", "452 4.2.2 mailbox full") in plain words: hard (the address does not work), soft (temporary) or policy (a provider rule, not the address), the provider and the next step. Free, read only. / Explica uma devolução ou erro SMTP em linguagem simples, com o próximo passo.
Parametersmessagerequired
generate_spf
Generate an SPF record / Gerar registro SPF
Builds one SPF record (TXT at the domain) from the services that send for it: includes, IPv4 and IPv6, mx and a. Starts with ~all (softfail), the safe choice; use policy fail (-all) once every sender is listed. Remember the limit of 10 DNS lookups (each include costs at least one). Free, no network. / Monta o registro SPF a partir dos serviços que enviam pelo domínio.
Parametersamxip4ip6policyincludes
generate_dmarc
Generate a DMARC record / Gerar registro DMARC
Builds one DMARC record (TXT at _dmarc.<domain>). Start with policy none and a report address (rua), read the reports, then move to quarantine and reject once every legitimate sender passes SPF or DKIM aligned. Free, no network. / Monta o registro DMARC; comece com p=none e suba para quarantine e reject.
How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.
Reached in the last 30 daysRequired25 pts
Auth declaredRequired10 pts
Tools listedRequired15 pts
DescriptionRequired15 pts
Logo10 pts
Publish an icon in the registry entry.
Documentation15 pts
Declare a GitHub repository with a README, or serve resource_documentation in the OAuth protected-resource metadata.
LicenseNot applicable
A hosted service is used under its provider's terms, so no license is expected here. This check is left out of the percentage.