ICAP for SMTP

g3proxy support to enable ICAP reqmod services for outgoing SMTP DATA message.

The SMTP message will be converted to an HTTP/1.1 PUT request, and then send to ICAP server. And the response from the ICAP server will be convert back to a SMTP message in the same format.

The following headers will be added in the ICAP request header:

• X-Transformed-From

  The value will be SMTP.

The following headers will be set in the HTTP PUT request:

• Content-Type

  The value will be “message/rfc822” for SMTP DATA message.

• X-SMTP-From

  The value will be the reverse-path part of the SMTP MAIL command, which will contain the sender’s Mailbox address.

• X-SMTP-To

  The value will be the forward-path part of the SMTP RCPT command, which will contain the recipients’ Mailbox address. There will be multiple of this header if there are more than one recipients.

The body of the HTTP PUT request will be the corresponding SMTP message data.

Not Implemented

• BDAT message.

• BURL message.

The not implemented extensions will be disabled by default in auditor’s smtp interception <conf_auditor_smtp_interception> config.