Unione
UniOne is an email delivery service offering a versatile Web API and SMTP API for sending transactional and marketing emails.
Verdict
Common use cases
- Validate recipient lists before bulk sends
- Cancel scheduled emails when campaigns change
- Pull delivery logs for support escalations
- Export event data for compliance audits
- Debug bounces and spam complaints in real time
Integration
- Vendor
- Unione
- Category
- other
- Auth
- API_KEY
- Tools
- 36
- Composio slug
unione
Tools
- Batch Email Validation
Tool to validate multiple email addresses in a batch. use when you need to verify deliverability for a list of emails at once.
- Cancel Scheduled Email
Tool to cancel a scheduled transactional email by its job id. use when you need to stop a pending email send before it's dispatched.
- Create Event Dump
Tool to create an asynchronous csv event dump. use when you need to export transactional email events for a specified time window.
- Delete Email Validation Requestdestructive
Tool to delete an email validation request. use when a validation job should be canceled by its id.
- Delete Tagdestructive
Tool to delete a specific tag. use when you have confirmed the tag id you wish to remove.
- Get Email Event
Tool to retrieve details of a specific email event by its id. use when you need event information for auditing or diagnostics.
- Get Email Send Job
Tool to retrieve detailed information about a specific email send job. use when you need its delivery metrics and history.
- Get Event Dump
Tool to retrieve the contents of a specific event dump. use when you have the dump identifier (from event-dump/create) and need its status and download urls.
- Resend Email Validation Results
Tool to resend results of an email validation request. use when you need to retrieve validation results again by request id.
- Resend Sent Email
Tool to resend a previously sent email by its job id. use when you need to trigger a resend of an email that has already been sent and you have the original job id.
- Resume Paused Email
Tool to resume a paused transactional email by its job id. use when you need to restart a paused pending email send.
- Retry Email Validation
Tool to retry an email validation request. updated to re-run validation via the official single validation endpoint using the provided email address.
- Schedule Email
Tool to schedule a transactional email up to 24 hours ahead. use when you need to send an email at a specific future time.
- Set Template
Tool to set or update an email template. use when you need to create or modify transactional email templates before sending messages.
- Set Webhook
Tool to set or edit a webhook event notification handler. use when you need to configure your webhook for event callbacks.
- Suppression List
Tool to return the suppression list since a given date. use when auditing bounced, unsubscribed, or blocked recipients.
- UniOne Email Balance
Tool to retrieve current account balance. use when you need to check your email usage and limits before sending large campaigns.
- UniOne Email Domain Management
Tool to manage sender domains in unione. use when you need dns records for verification, trigger verification or dkim checks, list domains, or delete a domain.
- UniOne Email Event Log
Tool to initiate an asynchronous export of email events (event dump). use when you need to export transactional email events for a specified time window.
- UniOne Email Event Types
Tool to retrieve supported email event types. use when you need a list of possible event codes for filtering or analytics.
- UniOne Email List (Export)
Tool to export email events within a specified time frame. it creates an asynchronous event dump which can later be downloaded and parsed using unione event dump get.
- UniOne Email Plan
Tool to retrieve current subscription plan details. use when you need to check your project and account plan limits before sending bulk emails.
- UniOne Email Pricing
Tool to retrieve current email pricing. use when you need to check per-email cost rates before sending emails.
- UniOne Email Quota
Tool to retrieve current email sending quota. use when you need to check your remaining quota before sending emails.
- UniOne Email Resubscribe
Tool to resubscribe a recipient who previously unsubscribed. use when you need to restore a user's subscription status after they opt in again.
- UniOne Email Schedule
Tool to schedule a transactional email up to 24 hours ahead. use when you need to send an email at a specific future time.
- UniOne Email SMTP Configuration
Tool to retrieve smtp server details and credentials. use when you need to configure your mail client or library for smtp sending.
- UniOne Email Statistics
Tool to retrieve email sending statistics over a specified time range. this action uses unione's event-dump aggregate api under the hood to compute daily statistics.
- UniOne Email Unsubscribe
Tool to unsubscribe an email from future emails. use when you need to stop all further transactional emails.
- UniOne Email Validate Result
Tool to retrieve the detailed result of an email validation request. updated behavior: uses the official single email validation endpoint to synchronously obtain full diagnostics for the provided email address.
- UniOne Email Validate Status
Tool to retrieve the current status of an email validation request. use when you need to poll for completion status.
- UniOne Email Webhook Types
Tool to retrieve supported email webhook event types. use when configuring your webhook callbacks.
- UniOne Event Dump List
Tool to retrieve the full list of event dumps. use when you need to view all existing event-dump tasks.
- UniOne Tag List
Tool to retrieve all user-defined tags. use when you need to fetch the full list of tags after authentication.
- UniOne Template List
Tool to list email templates. use when you need to retrieve available templates for transactional emails.
- Validate Email Address
Tool to validate an email address. use when you need deliverability diagnostics after compiling your recipient list.
Setup
Setup guide
- 11. Open your Switchy workspace and navigate to Settings > Integrations > Browse MCP Servers. 2. Search for Unione and click Connect. 3. You'll be prompted to paste an API key — log into your Unione account at unione.io, go to Settings > API Keys, and generate a new key with read and write permissions. 4. Copy the key and paste it into Switchy's prompt, then click Authorize. 5. Switchy confirms the connection and lists the 36 available tools. 6. To test, open any Space and type '@Unione validate this email: test@example.com' — the MCP should return deliverability status within seconds. 7. If the test fails, double-check the API key has not expired and that your Unione account is active. 8. Once verified, you can invoke any tool by @mentioning Unione and describing the task in plain language.
What teammates see: by default, memories from Unione are scoped to the Space (PROJECT visibility) - you can mark any memory PRIVATE or share it ORG-wide.
Works well with
Top models
Compatibility data appears once enough Spaces have used this MCP together with a given model.
How Switchy teams use it
Starter prompts
Validate Email List
@Unione validate these email addresses in a batch: alice@example.com, bob@test.io, charlie@demo.org. Return the status for each.Open in a Space →
Cancel Pending Send
@Unione cancel the scheduled email with job ID 78a3f2e1. Confirm once it's removed from the queue.Open in a Space →
Retrieve Delivery Metrics
@Unione get detailed information about email send job 5c9d8b12, including delivery status, opens, and any bounce reasons.Open in a Space →
Export Event Logs
@Unione create an event dump for all transactional emails sent between January 1 and January 31, 2025. Provide the download link once ready.Open in a Space →
Investigate Specific Event
@Unione retrieve the event details for event ID evt_9f4a2c7b. Show delivery timestamp, recipient actions, and any error codes.Open in a Space →
Example outputs
Illustrative - representative of the model's voice and quality, not literal recordings.
@unione validate this list of 50 subscriber emails from our last signup form and flag any that are likely to bounce
Batch validation submitted for 50 addresses. Results show 43 valid, 4 invalid (syntax errors or non-existent domains), and 3 risky (disposable email providers). The invalid addresses include two typos in common domains (@gmial.com, @yahooo.com) and two addresses at domains with no MX records. Risky addresses use temporary inbox services that may accept mail but expire quickly. Full report includes per-address deliverability scores and recommended actions.
This example demonstrates the batch validation tool's ability to catch common issues before sending. Note that validation consumes API credits per address checked, and results reflect deliverability likelihood at validation time — inbox status can change. Requires API key with validation permissions.
@unione cancel the scheduled welcome email job #job_abc123 — we just realized the promo code in the template expired yesterday
Scheduled email job #job_abc123 canceled successfully. This job was set to send 120 welcome emails starting in 45 minutes. No emails from this job have been dispatched yet. The job contained a batch send to new trial signups with subject line 'Welcome to Acme – Here's 20% Off'. You'll need to create a new send job with the corrected template once the promo code is updated.
Showcases the cancel tool's ability to stop sends before they go out — critical for catching template errors or outdated content. This only works for jobs still in 'scheduled' state; once emails start dispatching, individual messages can't be recalled. Requires the job ID from the original send request.
@unione pull all bounce and complaint events from the last 7 days, then summarize which sender domains are seeing the highest failure rates
Event dump created for the period March 15-22, covering 8,400 events. Download URLs provided for bounces.csv (340 hard bounces, 89 soft bounces) and complaints.csv (12 spam reports). Analyzing the data: sender domain 'promo.acme.com' shows a 9.2% hard bounce rate, significantly above the 2.1% average for your other domains. Most bounces are 'user unknown' errors, suggesting list hygiene issues. Domain 'support.acme.com' has the lowest bounce rate at 0.8% but received 8 of the 12 spam complaints, indicating possible content or frequency concerns.
Combines the event dump tool (async export of large event sets) with AI analysis to surface patterns. Event dumps take 30-120 seconds to generate depending on volume; the tool returns a job ID you poll until ready. This workflow is ideal for periodic health checks but not real-time alerting. Requires read access to event data.
Use-case deep-dives
When Unione wins for transactional email forensics
A 6-person SaaS team runs a 5-email onboarding sequence through Unione and notices 18% of users never receive the third email. The Get Email Event and Get Email Send Job tools let a support engineer trace each send by job ID, pull bounce codes, and confirm the issue is a validation failure on emails with plus-addressing. The team uses Batch Email Validation to pre-screen signups before queueing sends, cutting the drop-off to 3%. This MCP is the right call if your team sends fewer than 50k transactional emails monthly and needs one-off diagnostic access without building a dashboard. Beyond that volume, you'll want a dedicated observability stack. If your workflow is purely marketing campaigns (not transactional), Unione's tooling won't map to your send model.
When this MCP handles receipt-of-email disputes
A 3-person support team at a fintech startup fields 4-5 weekly tickets claiming "I never got the password reset email." The agent pulls the ticket, grabs the user's email from the CRM, and uses Get Email Event to retrieve the delivery timestamp, open status, and ISP response. In 80% of cases, the email delivered but landed in spam; the agent screenshots the event log and closes the ticket in under 2 minutes. The Create Event Dump tool exports a week's worth of sends when the team suspects a systemic deliverability dip. This MCP is ideal if your support volume is under 200 tickets monthly and email delivery is a recurring dispute category. If you're handling thousands of tickets, integrate Unione's webhooks into your ticketing system instead of querying per-case.
When Unione's cancel tool saves a mistimed send
A 4-person marketing ops team schedules a product launch email for 9am Pacific but realizes at 8:50am that the pricing table has a typo. The Cancel Scheduled Email tool takes the job ID (stored in their campaign tracker) and stops the send before it dispatches. The team fixes the template, reschedules for 10am, and avoids a support flood. This scenario works because Unione's API lets you cancel jobs programmatically—no dashboard login required. The trade-off: if your team schedules more than 20 sends per week, you need a staging/approval layer upstream, not a last-minute cancel button. This MCP is the right call for low-frequency, high-stakes transactional sends where a human reviews each job ID before dispatch.
Frequently asked
What does the Unione MCP let me do in Switchy?
It connects your Unione transactional email account so AI agents can send emails, validate addresses in bulk, cancel scheduled sends, and pull delivery event logs. You can automate email workflows — like triggering a send after a Slack message or validating a CSV of leads — without writing code or leaving Switchy.
Do I need admin access to connect Unione?
You need an API key from your Unione account, which typically requires admin or developer-level permissions to generate. The key grants full access to send emails and manage campaigns, so only connect it if you're comfortable giving the AI that level of control over your transactional email.
Can the Unione MCP send marketing emails or manage subscriber lists?
No. Unione is a transactional email service — the MCP is built for one-off sends, event tracking, and address validation. If you need bulk marketing campaigns or list segmentation, use a dedicated email marketing platform like Mailchimp or ConvertKit instead.
How is this different from just using Unione's API directly?
The MCP wraps Unione's API so any AI agent in Switchy can call it in plain English — no code required. You skip writing auth headers, parsing JSON responses, and chaining requests. If your team already has developers scripting Unione, the MCP won't add much; if you don't, it's the fastest way to automate.
Who on my team should connect the Unione account?
Whoever owns your transactional email setup and is comfortable sharing an API key with the workspace. Since the MCP can send emails and cancel jobs, treat it like handing someone the keys to your email infrastructure — usually a developer, ops lead, or technical founder.