On 2009-11-21 Jerry wrote: > I know that this has nothing directly to do with Postfix; however, I > figured the fastest way to get a serviceable answer would be here. > > I maintain a few Yahoo groups. I just received a bulletin from Yahoo > regarding the updating of their 'Groups'. > > <quote> > > Also in this release is a fix for group moderators who were having > issues approving pending messages via email. Moderators affected by > this issue were using email clients that (in violation of internet > standards) do not honor case in reply to addresses, meaning that they > would turn upper case letters into lowercase. Since the codes that > enable email moderation to work relied on the reply address being the > exact sequence of characters we were expecting, email moderation > commands did not work for these users. But we have now updated our > code in a way that will enable email moderation to work for even these > email clients, which should allow moderators to approve pending > messages and members via email once again. > > </quote> > > I was, perhaps incorrectly, of the opinion that case was not relevant > in e-mail addresses. I thought that there was an RFC that mentioned > this; although I cannot find one that specifically mentions case > folding on the reply to address. > > Is Yahoo's claim correct or are they simply trying to cover up for a > problem on their end?
Quoting from chapter 2.4 of RFC 2821: | Verbs and argument values (e.g., "TO:" or "to:" in the RCPT command | and extension name keywords) are not case sensitive, with the sole | exception in this specification of a mailbox local-part (SMTP | Extensions may explicitly specify case-sensitive elements). That is, | a command verb, an argument value other than a mailbox local-part, and | free form text MAY be encoded in upper case, lower case, or any | mixture of upper and lower case with no impact on its meaning. This | is NOT true of a mailbox local-part. The local-part of a mailbox MUST | BE treated as case sensitive. <http://www.ietf.org/rfc/rfc2821.txt> Regards Ansgar Wiechers -- "Abstractions save us time working, but they don't save us time learning." --Joel Spolsky
