Mailosaur MCP. Validate every email and SMS message flow.
Mailosaur gives your AI agent full control over virtual inboxes and SMS message streams. It lets you automate testing by listing, searching, retrieving content, and managing messages across multiple simulated servers. Use this MCP to instantly validate email delivery metrics and audit communication flows without ever touching a dashboard.
Give Claude and any AI agent real-world access
Lists all the virtual inboxes you own so you know which environments to check.
Creates a brand-new, clean virtual server/inbox for testing without affecting your live data.
Retrieves a complete list of every email and SMS message received by a specific test account.
Searches through thousands of messages, finding exactly what you need by sender, recipient, or subject line.
Gets the complete HTML and plain text body for any single message so your agent can analyze its specific contents.
Clears all messages from a server, or deletes individual messages permanently when testing is finished.
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What AI agents can do with Mailosaur: 8 Tools for Inbox Management
These tools let your AI client perform everything from creating new test environments to finding specific messages by sender or subject.
Make your AI actually useful.
Add this MCP to Claude, Cursor, or Windsurf and your AI stops guessing. It gets real tools to look things up, take action, and handle the stuff you keep doing by hand.
Start using Mailosaur MCPCreate Virtual Server
Creates a new, isolated virtual server or test inbox for dedicated testing periods.
Clear Server Inbox
Deletes every single message from an entire configured test server.
Delete Specific Message
Permanently removes one specific, undesirable message from a virtual inbox.
Get Message Content
Retrieves the full HTML and plain text content of any given test message for deep...
Get Server Details
Fetches specific information about a particular virtual server, such as its unique...
List Server Messages
Lists every message currently residing in a specified virtual server inbox.
Search Server Messages
Searches for specific messages by requiring detailed criteria like the sender, recipient, or subject line.
List Virtual Servers
Returns a list of all available virtual servers associated with your account ID.
Security and governance baked right in.
Pick your AI client below to get set up. Just create a Vinkius account, subscribe, and you're instantly up and running. We handle the entire backend infrastructure, delivering out-of-the-box support for HTTPS Streamable, SSE, and OAuth2—zero messy routing required.
Choose How to Get Started
Build a custom MCP for your own tools, or connect a ready-made integration from our catalog.
Build Your Own
Turn any API into an MCP. Import a spec, define Agent Skills, or deploy with MCPFusion.
- Import from OpenAPI, Swagger, or YAML specs
- Create Agent Skills with progressive disclosure
- Deploy to edge with MCPFusion framework
- Built in DLP, auth, and compliance on each call
- Real time usage dashboard and cost metering
- Publish to catalog or keep private
Make Your AI Do More
Start with Mailosaur, then connect any of our 5,200+ other servers whenever your AI needs more. One click, no limits.
- Use this MCP plus 5,200+ others, all in one place
- Add new capabilities to your AI anytime you want
- Connections are secured and governed automatically
- Track usage and costs across all your servers
- Works with Claude, ChatGPT, Cursor, and more
- New servers added to the catalog weekly
Independent Platform Disclaimer: Vinkius is an independent platform and is not affiliated with, endorsed by, sponsored by, verified by, or otherwise authorized by Mailosaur. All third-party trademarks, logos, and brand names are the property of their respective owners. Their use on this website is strictly for informational purposes to identify service compatibility and interoperability.
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Sandboxed per request
Zero-Trust Proxy
No stored credentials
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Policy on each call
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EU data residency
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~60% cost reduction
Checking delivery status shouldn't feel like detective work.
Today, checking if a critical message—like a password reset link or an order confirmation—actually made it through requires a lot of manual steps. You have to log into the email testing platform, find the correct virtual inbox domain, scroll through dozens of messages, and then copy-paste specific details (sender, subject, body text) into your debugging sheet.
With this MCP, you simply tell your agent what you're looking for. Instead of clicking through pages, your AI client executes a focused search using the tool’s criteria. You get instant results: a clean list of only the messages that matter, ready for immediate analysis.
Mailosaur MCP gives you full message lifecycle control.
The biggest time sinks disappear immediately. You stop having to manually check server domains; you just call `list_virtual_servers`. You eliminate the need to track down specific messages by hand, replacing it with a single prompt that executes a powerful search using criteria like sentTo or subject.
It’s simple: your agent manages the entire message lifecycle for testing. It can find the data, inspect the content, and when you're done, it clears the inbox completely. You move from hours of manual clicking to seconds of automated validation.
What Mailosaur MCP does for your AI
You can connect Mailosaur to your AI client and treat your test inboxes like any other data source. This lets you automate the tedious process of checking if a signup confirmation or an SMS code actually arrived, and what its content was. Instead of logging into multiple web panels, your agent reads directly from these virtual servers using simple natural language prompts.
Need to check messages sent only to a specific domain? No problem. You can also programmatically create new test environments when you need complete isolation for a fresh round of checks. When validation is done, you don't have to manually delete the evidence; just tell your agent to clear out the entire server inbox or permanently remove one bad message.
Because Vinkius hosts this MCP, your AI client can access all these testing tools from one place, making communication flow auditing simple and fast.
019d75cc-fc59-7297-800e-768ea48fcde3 How to set up Mailosaur MCP
The bottom line is you get programmatic access to complex email and SMS testing features through simple conversational prompts.
Subscribe to the MCP and provide your unique Mailosaur API key.
Connect this MCP to your preferred AI client (Cursor, Claude, etc.).
Use natural language commands—like 'Find all messages sent from billing@example.com'—and let your agent pull the data.
Who uses Mailosaur MCP
This MCP serves QA Engineers, backend developers, and operations teams who spend too much time logging into multiple web dashboards just to verify a single message was delivered correctly. It's for anyone whose job depends on validating automated communication.
Automates the validation of transactional emails or SMS codes, ensuring every required piece of data (like a password reset link) is present and correct.
Quickly inspects incoming test emails from services like Stripe or GitHub right from their IDE to debug why a webhook failed or what content was missed.
Monitors automated communication flows across multiple accounts and audits complex message histories without manual effort, confirming system health.
Benefits of connecting Mailosaur MCP
Instant Validation: Instead of manually checking a dashboard, your agent can run sophisticated searches using search_server_messages to find messages based on exact criteria like subject or sender domain. This saves hours of manual clicking.
Controlled Testing Environments: Need to simulate a fresh start? Use create_virtual_server to build entirely separate test accounts, ensuring that debugging one feature doesn't contaminate data for another.
Deep Content Inspection: Don't just confirm delivery; confirm the content. The ability to run get_message_content lets your agent read the full HTML body, guaranteeing links and required text blocks are present.
Clean Up Effortlessly: When testing is done, you can immediately reset your environment using clear_server_inbox. This keeps your data clean and prevents accidental review of old test messages.
Comprehensive Visibility: With one call to list_virtual_servers, your agent knows every server ID it needs access to. It gives a single pane of glass view over all your simulated communication channels.
Mailosaur MCP use cases
Debugging Failed Webhooks
A developer notices that the payment confirmation email isn't being generated correctly. They ask their agent to search_server_messages for 'Stripe Payment Failure' in the staging server, instantly retrieving the message content and seeing the exact missing parameter.
Auditing Communication Flows
An SRE needs to verify that all marketing campaigns sent last month were delivered. They prompt their agent to list_server_messages across three different server IDs, quickly confirming message count and status for a full audit report.
Validating Multi-Step Signups
A QA engineer is testing a new signup flow that requires an SMS code. They use the agent to create_virtual_server for isolation, then prompt it to find the expected 6-digit message via search_server_messages, confirming the code immediately.
Analyzing Specific Sender Behavior
An operations team needs to check if a third-party integration is sending spam. They ask their agent to filter all messages from that specific domain using advanced search and then use delete_specific_message on anything suspicious.
Mailosaur MCP tradeoffs
What to watch out for, and the recommended way to handle each one.
Manual Dashboard Browsing
Logging into the Mailosaur website, clicking through multiple domains, filtering by date range, and then manually copying message bodies to a spreadsheet.
Let your agent handle it. Use list_virtual_servers first, then direct the agent to use search_server_messages with defined criteria (sender/subject) and ask it to retrieve the data via get_message_content.
Assuming Message Location
Trying to manually check if a message is in 'Production' or 'Staging' without knowing which domain it uses, leading to missed data.
Always start by running list_virtual_servers to identify all available environments. This ensures your agent checks every necessary server ID before searching for anything.
Over-Retaining Test Data
Leaving hundreds of test messages sitting in the inbox, making it impossible for a human or AI to focus on current issues.
When testing is complete, run clear_server_inbox immediately. This keeps your environment clean and ensures you only deal with relevant message history.
When to use Mailosaur MCP
Use this MCP if your primary job involves programmatic validation of communication delivery—specifically email or SMS content, timing, and structure. You need to verify that a specific piece of data (like an API key or confirmation code) arrived inside the body of a message sent from an external source. It's ideal for QA automation pipelines, backend integration testing, and auditing multi-stage user flows.
Don't use this if you just need to manage general system metrics, like tracking how many people signed up today (that requires a different data source). Also, don't use it if your goal is simply writing code; you need the message content first. If you are only concerned with sending messages and not verifying receipt or content, this MCP isn't required because its focus is purely on retrieval, search, and management.
Frequently asked questions about Mailosaur MCP
How do I use Mailosaur MCP to check all my test inboxes? +
First, run list_virtual_servers to get a list of all your unique server IDs. Then, you can pass those IDs to the agent and ask it to search for messages across that entire set of servers.
Can I use Mailosaur MCP to validate SMS codes? +
Yes. The MCP treats SMS like email messages. You can use search_server_messages, specifying the expected sender or keyword in the body to find and verify those test codes.
What is the best tool for finding a message sent from a specific user? +
Use search_server_messages. This tool allows you to filter messages by detailed criteria, making it highly accurate when looking up sender or recipient addresses.
Does Mailosaur MCP allow me to create new test accounts? +
Yes. The create_virtual_server tool lets your agent programmatically build brand-new inboxes. This is critical for keeping different feature tests isolated from one another.
How do I get the full text of a message using Mailosaur MCP? +
Call get_message_content. This tool doesn't just show you the subject line; it retrieves the complete HTML and plain text body, which is necessary for deep data validation.