ICAP for IMAP

vey-proxy can use an ICAP REQMOD service for outgoing IMAP APPEND messages.

The mail message is converted into an HTTP/1.1 PUT request and sent to the ICAP server. The ICAP server’s response is then forwarded upstream.

The returned mail message must not change in size.

See also ICAP Request Headers for the ICAP headers that may be added for all ICAP adaptation requests.

The following protocol-specific header is added to the ICAP request headers:

• X-Transformed-From

  The value is IMAP.

The following headers are set on the HTTP PUT request:

• Content-Type

  The value is message/rfc822 for the IMAP message payload.

• Content-Length

  The value is the exact size of the mail message in the IMAP APPEND command. The ICAP server may modify the message body, but it must not change the total message size. The ICAP server should also return an updated Content-Length header in the HTTP request embedded in its ICAP response.

The body of the HTTP PUT request contains the mail message data.

Limitations

The ICAP server must not change the size of the mail message.