[Mailman-developers] Re: [meta-sig] mailman problems

John Viega jtv2j@cs.virginia.edu
Mon, 27 Apr 1998 11:28:32 -0400 (EDT)


> 
> >>>>> "KM" == Ken Manheimer <klm@cnri.reston.va.us> writes:
> 
>     KM> While i'm inclined to agree about the list-of-known-domains
>     KM> check being too maintenance intensive, i do see a reason to
>     KM> have the check in the first place.  The benefit comes into
>     KM> play when the web interface is in play - the user is there,
>     KM> and can get definite feedback about faulty addresses.  Without
>     KM> it, they only see address failures as the absence of any
>     KM> subscription confirmation - a decidedly vague and uncertain
>     KM> kind of feedback.
> 
> Couldn't we do the same sort of DNS lookup when the form is submitted?

Well, you can, but that would have a few problems of its own:

1) DNS lookup can be slow.  People want instant feedback.

2) Sometimes DNS is flakey, and you might reject a perfectly valid
email address.  Sendmail will just keep it in a queue and try again
periodically, so if it is a transient problem, then no problem.

I would say that perhaps the list of domains *should* stay, but not be
a requirement.  How about, the list gets checked, and gives you a
warning but not a fatal error if your address doesn't have one of the
listed endings?