Miles Fidelman:
> Ralph Blach wrote:
> >>> CASE FOLDING
> >>> All delivery decisions are made using the bare recipient
> >>> name (i.e. the address localpart), folded to lower case.
> >> http://www.postfix.org/local.8.html
> > Thanks, I discovered this and I personally consider this a bug. In
> > these days, users names need to be mixed case for security reasons.
> > If I have a domain name I could just run through a list of well known
> > names, and then fill it up with mail.
> >
> It's not so much a bug as a direct violation of the SMTP spec. RFC2821,
> par. 2.4, states:
>
> The local-part of a mailbox MUST BE treated as case sensitive. Therefore,
> SMTP implementations
> MUST take care to preserve the case of mailbox local-parts. ... In
> particular, for some hosts the
> user "smith" is different from the user "Smith"."
RFC 2821 defines SMTP mail. As required, Postfix does not case-fold
mail addresses when it relays SMTP email.
However, with LOCAL deliveries, Postfix case-folds the user name.
This improves interoperability (an issue that is mentioned in RFC
2821). The alternative is to do 2^N database file lookups for each
name of length N.
Wietse
