The request names Loops, so Loops comes first: it is email software for SaaS teams that sends transactional email and events via its API, with actions to send a transactional email, send an event and create a contact 111. Alternatives that send email through their own APIs are Resend 717, Mailjet 919 and Mailgun 818.
- 1
Loops APIloops.soverified and signed
Loops offers a send-transactional-email action using a pre-built template, a send-event action that can trigger automations, and a create-contact action for adding contacts 11.
+14 community tools built for it
for agents: send_transactional_email · send_event · create_contact
- 2
Resendresend.comverified and signed
Resend sends transactional and marketing email through an API, including a batch action for up to 100 emails per call and an action to retrieve a single email 17.
+12 community tools built for it
for agents: send_batch_emails · GET /emails/{email_id} · GET /emails/{email_id}
- 3
Mailjetmailjet.comverified and signed
Mailjet sends text, HTML or template email through its send-email action, with a custom API call option 19.
for agents: custom_api_call · send_email · email
- 4
Mailgunmailgun.comverified and signed
Mailgun sends email from a Mailgun domain through its send-email action, with a custom API call option 18.
+2 community tools built for it
for agents: custom_api_call · send_email · email
Sources
- 1Loops | Email Platform for SaaS: Marketing & Transactionalloops.so · read 2026-10-29
- 7Resend · Email for developersresend.com · read 2026-10-29
- 8Transactional Email API Service For Developers - Transactional Email API Service For Developers | Mailgunmailgun.com · read 2026-10-29
- 9Mailjet: Best Email Marketing Software & Email API for Teamsmailjet.com · read 2026-10-30
- 11Loops (Activepieces): declares "send_transactional_email" (the record we read and signed)unfragile.ai · read 2026-10-24
- 17Resend (Activepieces): declares "send_batch_emails" (the record we read and signed)unfragile.ai · read 2026-10-24
- 18Mailgun (Activepieces): declares "custom_api_call" (the record we read and signed)unfragile.ai · read 2026-10-24
- 19Mailjet (Activepieces): declares "custom_api_call" (the record we read and signed)unfragile.ai · read 2026-10-24
For agents: the 10 actions behind this answer
send_transactional_email · Loops (Activepieces) verified and signed
Send Transactional Email — Sends a transactional email to a contact using a pre-built template in Loops.
· Loopstack website read, tools not yet checked
Loopstack is a TypeScript framework based on NestJS for building AI agents and durable AI workflows. Open source.
add-new-jit-ee-api · add-new-jit-ee-api verified and signed
Add a new API to the JIT-VM (aka JIT-EE) interface in the codebase.
email-sending-get-email-message · Cloudflare API verified and signed
Fetch an email message
custom_api_call · GitHub (Activepieces) verified and signed
Custom API Call — Make a custom API call to a specific endpoint
slack-find-user-by-email · Slack (Activepieces) verified and signed
Find User by Email — Finds a user by matching against their email address.
send_batch_emails · Resend (Activepieces) verified and signed
Send Batch Emails — Send up to 100 emails in a single API call
custom_api_call · Mailgun (Activepieces) verified and signed
Custom API Call — Make a custom API call to a specific endpoint
custom_api_call · Mailjet (Activepieces) verified and signed
Custom API Call — Make a custom API call to a specific endpoint
select_organization · agentmail-mcp verified and signed
Choose which organization your AgentMail operations target (for users who
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