lda_original_recipient_header overrides RCPT TO?

[Gedalya]

Hi all,

The example config says:

# Header where the original recipient address (SMTP's RCPT TO: address) is taken
# from if not available elsewhere. With dovecot-lda -a parameter overrides this.
# A commonly used header for this is X-Original-To.
#lda_original_recipient_header =

I'm using dovecot 2.2.19

The "if not available elsewhere" bit seems to hold true for LDA, but not for LMTP.
That is to say, if the value I want used is passed with LDA using the -a option, and another one I want ignored is passed in the header specified in this option, it works correctly and I have the address detail in sieve. However when using LMTP and the desired value is passed as RCPT TO, and this option is defined, and such a header exists -- its value seems to take effect, and is matched by sieve as the envelope address.