Wietse Venema:
> I've done a proof-of-concept implementation that works as documented
> below the signature.
I was able to simplify this further. The result is below.
Comments are welcome.
The problem with forward_path could be solved without requiring
changes to the forward_path default setting:
forward_path = $home/.forward${recipient_delimiter}${extension},
$home/.forward
When Postfix expands this while delivering mail, it now replaces
${recipient_delimiter} with the actual recipient delimiter in the
recipient email address, instead of using the main.cf value.
recipient_delimiter (default: empty)
The set of characters that can separate user names and
address extensions (user+foo). See canonical(5),
local(8), relocated(5) and virtual(5) for the effects
this has on aliases, canonical, virtual, and relocated
lookups. Basically, the software tries user+foo before
trying user.
When the recipient_delimiter set contains more than one
character (Postfix 2.11 and later), user names and
address extensions are separated at the first character
that matches the recipient_delimiter set. The
implementation recognizes only one delimiter character
per email address.
When used in forward_path, ${recipient_delimiter} is
replaced with the actual recipient delimiter in the
recipient email address.
Examples:
# Support Postfix and qmail extensions (Postfix >= 2.11).
recipient_delimiter = +-
# Use .forward for mail without address extension, or
# with an unrecognized address extension.
forward_path = $home/.forward,
$home/.forward${recipient_delimiter}${extension}
This seems like a more reasonable implementation.
Support for delimiter priorities could be added later but I doubt
that it will really solve problems.
Wietse
