MailStream is itself the product named in the request: a platform for sending physical mail (postcards, letters, checks) at scale via API, MCP server, or dashboard, with printing and shipping in 1 to 2 business days 1. For sending email rather than physical mail, the closest options are Resend, SendGrid, Mailgun and Mailkite.
- 1
MailStreammailstream.appwebsite read, tools not yet checked
Sends postcards, letters and checks at scale, printed and shipped in 1 to 2 business days, with address verification and tracking, via API, MCP server or self-serve dashboard 1.
official:MCP server · MailStream
- 2
Resendresend.comfound in code, not yet checked
Sends transactional and marketing email through an API and SDKs for common programming languages 2.
+12 community tools built for it
for agents: create-api-key · send-email · send-broadcast
- 3
SendGrid Email APIsendgrid.comverified and signed
Sends email through a transactional email API and marketing campaigns platform, now available through Twilio.com 3.
official:API · Email Activity (beta)+12 community tools built for it
for agents: POST_mail-send · send_email · Mail
- 4
Mailgunmailgun.comverified and signed
Sends, receives and tracks email through transactional email APIs built for developers 4.
+2 community tools built for it
for agents: send_email · custom_api_call · email
Sources
- 1The complete platform for physical mailmailstream.app · read 2026-10-29
- 2Resend · Email for developersresend.com · read 2026-10-29
- 3SendGrid Email API and Email Marketing Campaigns | Twiliotwilio.com · read 2026-10-29
- 4Transactional Email API Service For Developers - Transactional Email API Service For Developers | Mailgunmailgun.com · read 2026-10-29
For agents: the 10 actions behind this answer
· MailStream website read, tools not yet checked
MailStream is the complete platform for physical mail. Send postcards, letters, and checks at scale via API, MCP server, or self-serve dashboard, printed and shipped in 1 to 2 business days.
create-api-key · Email Sending MCP found in code, not yet checked
POST_mail-send · Email Activity (beta) verified and signed
v3 Mail Send
send_email · Mailgun (Activepieces) verified and signed
Send Email — Send an email using your Mailgun domain
· Mailkite website read, tools not yet checked
Receive any message as a webhook, send with one API across unlimited domains and mailboxes, free. No mail server, no MX/SPF/DKIM/DMARC to rebuild for every launch. The email platform for developers, teams, and the agents they build.
select_organization · agentmail-mcp verified and signed
Choose which organization your AgentMail operations target (for users who
Sending · Sendmux A2A verified and signed
Send email and manage outbound attachments through Sendmux sending routes.
sendEmail · primitive.dev verified and signed
Use this when the user has confirmed a new outbound email. Sends real email through Primitive's relay and can wait for the first SMTP delivery outcome.
email · mailslurp-client verified and signed
send-email · MCP Mailtrap Server found in code, not yet checked
Send an email to your recipient email address using Mailtrap Email API. You can send emails to multiple recipients at once.
Labels are the instruments' verdict and are never changed by ranking. Agents and robots get this same answer as JSON at /api/v1/find?q=…&answer=1 and through the MCP server.