[CentOS] login case sensitivity

[hw]

Gordon Messmer wrote:
> On 09/07/2017 08:11 AM, Stephen John Smoogen wrote:
>> This was always
>> problematic because DNS hostnames and email addresses in the RFC
>> standards were case insensitive
>
>
> Not quite.  SMTP is required to treat the "local-part" of the RCPT argument as case-sensitive, and to preserve case when relaying mail.  The destination is allowed to treat addresses according to local policy, but in general SMTP is case sensitive with regard to the user identifier.

Last time I checked, RFCs said that local parts *should not* be case sensitive,
and cyrus defaulted to treat them case sensitive, which is a default that usually
needs to be changed because senders of messages tend to not pay any attention to
the case sensitiveness of recipient addresses at all, which then confuses them like
any other error.