Bug#522807: exim4-config: RCPT ACL rejects valid local parts by default

[Andreas Metzler]

On 2009-04-06 David Sheldon <dave-debian at earth.li> wrote:
> Package: exim4-config
> Version: 4.69-9
> Severity: minor

> By default the configuration will not accept emails with local parts
> containing a set of rfc-valid characters, which are considered
> dangerous (@,%,!,/,|,` etc).

> It says that if you want you can make this list less restrictive, but if the
> default is to reject such mails then we're breaking Postel's Law
>   "be liberal in what you accept from others."

> If I had an address with those (valid) characters in, then there's not much
> point configuring my server to receive emails for it, if it never gets there
> because one of the servers in between rejects it.

> This is really a compromise between protecting users against themselves and 
> keeping the internet free of random blockages.
[...]

As you can probably guess this is done deliberatly, since imho
it is on the right side of the latter dichotomy (protecting users
against themselves). This is a rather ancient feature (already there
in 2005) which mirrors the respective settings in upstream's default
configuration file.

cu andreas
-- 
`What a good friend you are to him, Dr. Maturin. His other friends are
so grateful to you.'
`I sew his ears on from time to time, sure'