sendmail invocation for "empty sender" bounces

[Kjetil Torgrim Homme]

On Sat, 2006-10-14 at 00:18 +0200, Sebastian Maus wrote:
> bounce generation with the "empty sender" address is done like this in
> several places in the source code:
> 
> [...]
>      smbuf[0] = "sendmail";
>      smbuf[1] = "-i";            /* ignore dots */
>      smbuf[2] = "-f";
>      smbuf[3] = "<>";
> [...]
> 
> Unfortunately, "<>" is not recognised as the "empty sender" by our
> sendmail implementation. Instead, it expects "" (which looks a lot more
> logical to me, too, given that < and > may not be part of an email
> address which is what is expected to come after the -f).

then it's not a Sendmail compatible interface, and you should report the
bug to your MTA provider.  plenty of software will expect this to work.
the <> are optional around an address.  well, unless you put the address
right after -f, obviously -f"" won't work :-)  -f"<>" will, however.

> While my own tests with Postfix, Debian SMail and qmail were all
> positive, Sendmail 8.11.3 invented some envelope sender address and
> thus failed the test. With Sendmail, "<>" must be used to force the
> empty sender. I do not have any newer Sendmail at hand to test.

FWIW, sendmail -f "" works equivalently to sendmail -f "<>" on the
Sendmail 8.13.7 running on my home computer.

> From this small set of tested environments, I guess that -- for the
> sake of compatibility with Sendmail -- a source code change within
> Cyrus is not very likely. Is there a definition/description of the
> sendmail interface somewhere (other than "the way Sendmail did it")?

isn't that enough? :-)
-- 
Kjetil T.