Re: [dane] Encoding local parts in better ways

[Viktor Dukhovni <[e-mail]>]

On Tue, Oct 06, 2015 at 03:44:29PM -0400, John R Levine wrote:

> >Many systems allow "extensions" such as john-ext or mary+ext
> >
> >The term used in the vernacular is "sub-addressing" (in everything that I
> >have seen), and the term in [RFC5233] is "subaddressing" (no hyphen) or
> >"detailed addressing" (with space). "Plus addressing" (occasionally
> >"plus-addressing") and "minus addressing" or "'minus' addressing" has also
> >been seen in the wild. I would change that sentence to say that:
> 
> Depends what mail software you're used to.  In qmail land they're definitely
> extensions, but I'll note they're also called subaddresses.

Yes, Qmail and Postfix both call these address extensions.

With Exim, an extension appears to be called a "local part suffix".

Note that in all three the term applies to the extra bits appendded
to the base address.

The Postfix pipe(8) delivery agent supports macros to construct
delivery command arguments from the recipient address.

    Given a recipient address of [e-mail]

    ${recipient} == [e-mail]
    ${mailbox} == joe+tag
    ${domain} == example.com
    ${user}     == joe
    ${extension} == tag
    ${nexthop} == <nexthop> from "mailer triple":
                  (<transport a.k.a. mailer>, <nexthop>, <recipient>)

Surely TMI, but the point I am trying to make is that the terminology
varies widely.  These are "local" matters, and each MTA uses its
own language to describe its interface.

-- 
	Viktor.