[IRCServices] Email forwarding

Imran Ali Rashid u970042 at giki.edu.pk
Mon Jan 22 04:29:46 PST 2001


>      That's my point.  _Something_ will choke, be it sendmail, the system
> (too many processes), or Services SENDPASS (MTA refuses messages due to
> load). Switching MTAs just moves the problem around.

You're assuming sendmail isn't correctly configured...
Configure it properly and it shouldn't choke.
I won't go into details about how you're a VERY bad
sys admin if this isn't set. :-)
In sendmail.cf:
MaxDaemonChildren=limit
make sure that limit is set and reasonable.

About services choking, I think the original idea of having a
separate process run via cron say every hour is a better idea.
That way, services don't choke.

And if some networks think that this isn't a good idea, make
the email address feature a compile time option.

Nothing is bullet proof, but everything is manageable.
Like the max process limit in sendmail. and the DNS query
timeout limit also.

> >>Lather, rinse, repeat and watch sendmail choke.

Hmm what other possible problems could there be. How
about checking to see if an email address is already in queue.
If it is, then don't send the mail again. That should be simple
enough.
Another thing that could be done is to set a flag in the nickname,
to restrict the number of emails. Say one every 10 hours or so.

Imran Ali Rashid

----- Original Message -----
From: "Andrew Church" <achurch at achurch.org>
To: <ircservices at ircservices.za.net>
Sent: Monday, January 22, 2001 4:15 PM
Subject: Re: [IRCServices] Email forwarding


> >>>What part of this is open to resource attacks?
> >>
> >>/ns set email some-domain at that.doesnt.resolve
> >>/ns sendpass
> >>
> >>Lather, rinse, repeat and watch sendmail choke.
> >
> >Depends heavily on your choice of MTA.  Sendmail may behave like this but
> >Exim [http://www.exim.org/] sure doesn't...  however putting limits on is
> >still a good idea due to the extra resources consumed by having N number of
> >Exim processes waiting for their domain resolvers.
>
>      That's my point.  _Something_ will choke, be it sendmail, the system
> (too many processes), or Services SENDPASS (MTA refuses messages due to
> load). Switching MTAs just moves the problem around.
>
> >(In case you were wondering, I rather like Exim - readable config files,
> >completely bulletproof, [...]
>  ^^^^^^^^^^^^^^^^^^^^^^
>      Ain't None Such.  You mean "not banged on enough".
>
>   --Andrew Church
>     achurch at achurch.org | New address - please note.
>     http://achurch.org/ | $B%a!<%k%"%I%l%9$,JQ$o$j$^$7$?!#(B
>
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