Sieve received MTA option

Sieve access to local Received: field
Sieve scriptsare necessarily evaluated after messages are received but before messages are enqueued to specific recipients. The MTA tries to include as much information in Received: fields as possible, which means deferring Received: field generation until the actual enqueue operation is performed. This means that Sieve scripts are not able to "see" the outermost Received: field that appears on the message.

Although most of the information in the outermost Received: field is available through other means, not all of it is, and even if it is available it may not be convenient to access it through other mechanisms. So the MTA normally adds reasonable approximation to the final Received: field to the message header prior to Sieve script evaluation. This addition is controlled by the  MTA option. A value of 1 (the default) enables the addition of this Received: field while a value of 0 disables it.

See also:
 * Sieve filters
 * Sieve filter interpretation MTA options