Additional information. I've cited the man page of virtual but in the
test I've mentioned, I've used local delivery. In local(5), the
information is more interesting but still no clear explanation:
CASE FOLDING
All delivery decisions are made using the bare recipient name (i.e. the
address localpart), folded to lower case. See also under ADDRESS
EXTENSION below for a few exceptions.
There is no explicit information on case folding in ADDRESS EXTENSION section...
Additionally, the man page says "all delivery decisions", but it
doesn't say anything about rewriting the envelope recipient address
with a case folded equivalent.
Regards
Fedor
2018-10-18 21:23 GMT+02:00, Fedor Piecka <teplav...@gmail.com>:
> Hello
>
> I'm implementing a new feature in our mail system which uses address
> extensions for message delivery to user inbox subfolders.
>
> I've found out that alias expansion folds case not only of user part of
> address (before +), but it also folds the address extension (after +).
>
> I've setup a basic Postfix(3.3.1) configuration for the purpose of testing
> with the following settings:
>
> local_recipient_maps =
> mailbox_transport = smtp:127.0.0.1:2525
> recipient_delimiter = +
> propagate_unmatched_extensions = canonical,alias
>
>
> Alias file contains a single line:
> john.doe: doe
>
>
> If I send 2 messages through SMTP, one addressed to
> "doe+CamelCase@testhostname", the other to
> "john.doe+CamelCase@testhostname",
> this is what happens:
>
> postfix/smtp[17600]: 43D3D29F15: to=<doe+CamelCase@testhostname>,
> relay=127.0.0.1[127.0.0.1]:2525, delay=0.16, delays=0.02/0.02/0.07/0.05,
> dsn=2.0.0, status=sent (250 2.0.0 OK: queued as
> <4213941.17397.14824888156065723605@localhost.localdomain>)
> postfix/smtp[17600]: 952B929F15: to=<doe+camelcase@testhostname>,
> orig_to=<john.doe+CamelCase@testhostname>, relay=127.0.0.1[127.0.0.1]:2525,
> delay=0.1, delays=0.01/0/0.04/0.05, dsn=2.0.0, status=sent (250 2.0.0 OK:
> queued as <4214170.17397.13366994128348457886@localhost.localdomain>)
>
> The first one is delivered correctly into CamelCase mailbox and the other
> is delivered to the camelcase mailbox.
>
> I think this is an undesired behavior as the handling of address extensions
> for aliased and non-aliased users is different. Aliased users cannot use
> uppercase letters in IMAP folder names if they want to allow direct
> delivery into them.
>
> I've searched through the documentation for any explanation/solution. It
> isn't clear from the docs whether such a folding should be done. From
> virtual(5):
>
> The *propagate_unmatched_extensions
> <http://www.postfix.org/postconf.5.html#propagate_unmatched_extensions>*
> parameter controls whether an
> unmatched address extension (*+foo*) is propagated to the result of
> table
> lookup.
>
> and:
>
> The search string is folded to lowercase before database lookup. As
> of
> Postfix 2.3, the search string is not case folded with database
> types
> such as regexp <http://www.postfix.org/regexp_table.5.html>: or
> pcre <http://www.postfix.org/pcre_table.5.html>: whose lookup fields
> can match both upper and
> lower case.
>
>
> I would expect the "propagate_unmatched_extensions" option to work
> consistently and without case folding.
>
> Do you have a different opinion?
>
> Regards
> Fedor
>
