Re: [exim] docs nit

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Author: W B Hacker
Date:  
To: exim users
Subject: Re: [exim] docs nit
Jeremy Harris wrote:
> http://exim.org/exim-html-4.63/doc/html/spec_html/ch11.html#SECTexpvar
>
> Is $domain already lower-cased? The docs don't say one way or the other.
> What about $original_domain and $parent_domain?
> $sender_address?
>
> Note that $local_part is specified for this.
>
>
> Thanks,
>    Jeremy

>


IIRC, the internet specifications are that <domain>.<tld> *must* be lower-case.

To an(y) MTA, that oridinarily applies to all characters 'to the right' of the
'@' symbol.

- so - no need for an MTA to handle those as anything but lower-case, and
'folding' to lower case is in order if needed.

Local part - 'to the left' of the '@' symbol, may be upper/lower/mixed case, and
supposedly is to be preserved and conveyed unaltered by an MTA.

Many MTA settings have instead 'folded' these to lower-case, and/or performed
and either-case lookup match, so as to not reject mail which might 'humanly'
have been addressed imprecisely.

If you have need of case-sensitivity, Exim can be configured to do either/both -
as needed. See 'caseful_local_part'. Might also be useful to have 'aliases' or
more than one router.

NB: Some of this may fall apart as non-ASCII <domain>.<tld> increase - but
that's a whole 'nuther issue.

HTH,

Bill