On 1/24/07, gwtmp01 / mac.com <gwtmp01 / mac.com> wrote:
>
> On Jan 24, 2007, at 2:22 PM, Alex LeDonne wrote:
> > If you're going to use exec, you need to process those address bits
> > separately to find the SUBSET of RFC2822 addresses that your process
> > is willing to accept. Because with enough quoting and escaping, I can
> > send almost anything as the sender of an e-mail message.
> >
> > Unless you have a strong use case otherwise, I suggest allowing only
> > [-_.a-zA-Z0-9]
>
> I generally agree with Alex, but I would suggest allowing a '+' also.
> The reason being is that
>
>    local+anything / domain.com
>
> is often interpreted to cause the message to be delivered to
>
>    local / domain.com
>
> It is an easy way for a single 'user' with one mailbox to actually have
> an infinite number of email addresses.  I'm not sure if this
> interpretation
> is mandated by the standard or is just common practice.
>
> Gmail is an example of an email service that supports this concept.
>
>
> Gary Wright
>

Good call, Gary, thanks for the reminder. Some MDAs (Courier
maildrop's in default config, for example) use + as a delivery folder
designator.

-Alex


"Speaking of GMail" trivia: Gmail not only allows the +, but ignores
dots in the local-part in delivering mail.
http://mail.google.com/support/bin/answer.py?ctx=%67mail&hl=en&answer=10313