Mails.so

email 3 tools available

Mails is an API service that provides powerful email validation capabilities to help maintain a clean and effective email list.

Connect Mails.so Visit Mails.so

About this integration

Connect Mails.so to Definable to triage inboxes, draft and queue follow-ups, classify and route incoming threads. Personas call Mails.so's 3 tools directly from chat or scheduled flows. Hand off to an email persona to triage, draft, and route — with you in the loop on every outbound.

Connect Mails.so to Definable and it becomes a set of typed tools your agents plan with — triggered by events, run on schedules, or invoked mid-conversation. Every write is checked by the verifier before it lands.

Auth OAuth2 · 2 clicks

Tools 3 exposed

Plans All, incl. Free

Data Never trained on

Mails.so · in workflows

What teams actually run.

Three patterns teams run with Mails.so on day one. Each one is a plain-English prompt — no canvas, no glue code — and you can remix them into anything.

Inbox triage

│ Read incoming threads

│ Classify by intent + urgency

└ Draft replies for review

Auto-follow-up

│ Detect emails awaiting reply for 3+ days

│ Draft contextual nudges

└ Queue for one-click send

Lead capture

│ Listen for inbound from a form alias

│ Extract details

└ Push to the CRM

3 tools available

The Mails.so toolbox.

Every Mails.so capability your agents can call, each with a typed schema the planner reads. The router picks the right tool per step; the verifier checks the result.

Retrieve Batch Results

Tool to retrieve results of a bulk validation job. Use after submitting a batch and you have its ID.

Validate Bulk Emails

Tool to validate multiple email addresses in bulk. Use when you need to confirm deliverability of a list of emails at once.

Validate Single Email

Tool to validate a single email address. Use when you need to check deliverability and quality details before sending an email.

See it run

One prompt, start to finish.

A real prompt, the Mails.so tools it calls, and what comes back. This is the whole interface — describe the outcome, agents handle the rest.

❯

Run a real Mails.so task end-to-end — plan it, execute across the API, and hand back a verified result.

mails_so.retrieve_batch_results Tool to retrieve results of a bulk validation job. Use after submitting a batch and you ha

mails_so.validate_bulk_emails Tool to validate multiple email addresses in bulk. Use when you need to confirm deliverabi

mails_so.validate_single_email Tool to validate a single email address. Use when you need to check deliverability and qua · verified

done

Done. Mails.so responded across 3 calls, the verifier signed off, and the result is logged with every payload.

FAQ · Mails.so

Questions, answered.

What teams ask before connecting Mails.so.

01 What can I automate with Mails.so on Definable?

Anything Mails.so exposes through its API. Common email workflows on Definable include triage inboxes, draft and queue follow-ups, classify and route incoming threads. Personas can call any of the 3 Mails.so tools directly, then chain the result into another integration without you writing code.

02 How does Mails.so authentication work?

Mails.so uses API_KEY on Definable. You connect once from the integrations page, scoped to the permissions you choose, and from then on any persona that has the integration enabled can act on your behalf. Tokens are encrypted at rest and rotated automatically.

03 Is the Mails.so integration included in my Definable plan?

Yes — every Definable plan, including Starter, includes access to all 3 Mails.so tools. You only need a separate Mails.so subscription if Mails.so itself charges per seat or per API call.

04 Is using Mails.so through Definable secure?

Every call from a persona to Mails.so is logged with the user, persona, prompt, and response. Tokens never leave Definable's secrets vault, scopes are configurable per persona, and you can revoke access at any time from the integration page.

05 How do I get started with Mails.so on Definable?

Sign up for Definable, open the integrations page, find Mails.so, and connect via OAuth or API key. You can immediately attach Mails.so to any persona and start running workflows. The free Starter plan includes 5,000 credits/month.

06 What Mails.so actions does Definable expose?

Definable exposes all 3 Mails.so actions as callable tools — including `Retrieve Batch Results`, `Validate Bulk Emails`, `Validate Single Email`. Each tool gets a typed parameter schema so personas know exactly how to call it.