Case sensitive usernames and sendmail - mystic voodoo

Polytropon freebsd at
Mon May 27 01:47:16 UTC 2013

On Sun, 26 May 2013 18:36:41 -0700, Michael Sierchio wrote:
> On Sun, May 26, 2013 at 6:17 PM, Polytropon <freebsd at> wrote:
> >
> > On Sun, 26 May 2013 18:44:41 -0600, Modulok wrote:
> > > I know usernames are case-sensitive, I thought emails were
> > > too.
> >
> > If I remember e-mail basics correctly: No. They're not.
> > For example, foo at, FOO at and Foo at
> > and all upper/lowercase variations are the same as foo at
> >
> You remember incorrectly ;-)

I checked again - and yes, it seems that my memory about
the valid definition has changed to what is reality today,
i. e. sendmail "rewriting" uppercase to lowercase prior to
further processing.

> The local part of an address (before the @ sign) is case-sensitive (with
> the exception of postmaster at

So it depends on how sendmail is configured that "it does
not matter today".

> Everything to the right of the @ is indeed case insensitive, but everything
> to the left might be case sensitive, depending on local policy.  This means
> you must preserve the case of everything to the left of the @ sign.

According to the link provided by Erich Dollansky, FreeBSD's
default setting of

	Mlocal,           P=/usr/libexec/mail.local, F=lsDFMAw5

needs to be added the "u" option to the F= parameter to preserve
the uppercase letters in the the left side (username) of the
address. Maybe this additiion is required in other cf files
containing Mlocal settings too? Of course it would be nice if
there was a corresponding setting for the mc files which the
cf files are usually generated from...

Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...

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