ionos-smtp

name	ionos-smtp
version	0.1.0
description	Compose and send email via IONOS SMTP with attachments, threading, inline images, and optional queue-based async delivery.
tags	["smtp","email","ionos","mail","mcp","send"]
metadata	{"clawdbot":{"emoji":"📤","requires":{"bins":["python3"]}}}
env	{"IONOS_SMTP_USERNAME":{"description":"Full IONOS email address","required":true},"IONOS_SMTP_PASSWORD":{"description":"IONOS SMTP password","required":true}}

IONOS SMTP Mail Send

Outbound mail capability through IONOS SMTP. Composes MIME messages, authenticates, handles attachments and inline images, and optionally queues for retry. Does not generate content — upstream skills produce the message payload.

Composes with the IONOS IMAP skill: sent messages are APPENDed to the IMAP Sent folder so the mailbox reflects reality across clients.

MCP Tools Quick Reference

Tool	Purpose	Mode
send_message	Compose and send synchronously	Sync
send_reply	Reply with correct threading headers	Sync
queue_message	Enqueue for async send (requires queue mode)	Async
queue_status	Query send status by queue ID	Query
test_connection	Verify auth + TLS without sending	Query
validate_addresses	RFC 5322 syntax check	Query

Usage Patterns

Simple send:

send_message(
    to=[{"name": "Jane", "email": "[e-mail]"}],
    subject="Hello",
    text="Plain text body",
    html="<p>HTML body</p>"
)

Reply with threading:

send_reply(
    folder="INBOX",
    uid="12847",
    text="Thanks for following up!",
    reply_all=false,
    quote_original=true
)

Bulk send via queue:

queue_message(
    to=[{"email": "[e-mail]"}],
    subject="Proposal",
    html="<p>See attached.</p>",
    attachments=[{"path": "/tmp/proposal.pdf", "filename": "Proposal.pdf", "content_type": "application/pdf"}],
    custom_headers={"X-Campaign-Id": "abm-2026-q2"}
)

Send Receipt Schema

{
  "ok": true,
  "message_id": "<[e-mail]>",
  "accepted_recipients": ["[e-mail]"],
  "rejected_recipients": [],
  "smtp_response": "250 2.0.0 Ok: queued",
  "sent_at": "2026-04-17T14:22:10+00:00",
  "appended_to_sent": true
}

Error Codes

Code	Meaning	Retryable
auth_failed	Bad SMTP credentials	No
connection_timeout	Network unreachable	Yes
tls_negotiation_failed	TLS handshake error	Yes (once)
recipient_rejected	550 from server	Partial — check rejected_recipients
message_too_large	Exceeds size limit	No
rate_limited	Local or remote rate limit	Yes
malformed_message	Invalid MIME input	No
attachment_unreadable	Path not found / not readable	No

IMAP Integration

• send_reply fetches the original message via the IMAP skill for threading
• APPEND to Sent copies sent messages to the IMAP Sent folder
• Both features are configurable — skill works without IMAP at reduced capability

Security

• Credentials never logged or returned in tool output
• Password sent only over established TLS
• From address validated against authenticated account
• BCC stripped from headers, delivered via envelope only