> > It is not recommended to rely on local-part case, but it is indeed > case-sensitive. > > And this is to avoid such issues that postfix supports address > cleanup/canonicalisation before forwarding mails to dovecot. > > ---------- > RFC 5321: > > "Local-part = Dot-string / Quoted-string ; MAY be case-sensitive > […] > While the above definition for Local-part is relatively permissive, for > maximum interoperability, a host that expects to receive mail SHOULD avoid > defining mailboxes where the Local-part requires (or uses) the > Quoted-string form or where the Local-part is case-sensitive." > >
And therefore “receive liberally” policy that wants to assume case-insensitivity should single-case the address IN THE COMPARISON. > >
