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Sending mail

POST /messages/send sends a message from one of the account’s addresses:

Terminal window
curl https://api.mailcycle.email/messages/send \
  -H "Authorization: Bearer $MAILCYCLE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "receipts-x7k2@example-pool.email",
    "to": "someone@example.com",
    "subject": "Hello",
    "text": "Plain text body"
  }'
{ "sent": true, "messageId": "<…>" }
Field Notes
from Required. An address on this account. Any other returns 403 not_your_address.
to Required. One recipient.
subject Required. Up to 998 characters.
text Required. Up to 200,000 characters.
html Optional. Up to 200,000 characters.

Sessions and API keys can send; device credentials cannot. An address paused after a missed payment returns 403 address_paused.

Sent mail passes through in plain text and is not stored. Sending is limited to 60 messages an hour per account. Mailcycle is not a bulk or marketing sender.