Nigel,
thanks for your e-mail. It gave me a big "ahaaa" but unfortunately
I am still a little bit confused:
> >> Fetchmail manual however suggests that
> >> the MTA stores one e-mail per recipient in the box although it is
> >> actually the same box and adding proper Envelope-To or X-Envelope-To
> >> headers.
>
> > I do not know if you can ask exim to "explode" the message into single
> > ones (except some "loop" delivery to itself).
>
> Set batch_max=1 on the appendfile transport you are using.
>
> See
> http://www.exim.org/exim-html-current/doc/html/spec_html/ch25.html
According to this link, the default for batch_max is 1 which should result
in no batching at all. However we have not used batch_max so far in
our local transport:
local_delivery_mysql:
driver = appendfile
delivery_date_add
envelope_to_add
return_path_add
#group = mail
#user = mail
mode = 0660
directory_mode = 770
mode_fail_narrower = false
maildir_format
directory = ${lookup mysql{MYSQL_LOCALUSER_HOME}{$value}{'fail'}}
Thus, we assume that the default of batch_max is active (1) but we still
see e-mails with multiple recipients pointing to the same postbox
only once.
Happy for any advice
Sascha