[ On Saturday, July 5, 2003 at 15:37:24 (+0530), Suresh Ramasubramanian wrote: ]
> Subject: Re: [Exim] Brain Dead ISP's?
>
> Be warned, however, that rejecting at any stage than just after RCPT TO tends
> to make at least some broken MTAs interpret this as a temporary / 4xx
> failure, and then they start to pound multiple times on your box - several
> times a minute, quite often.
So long as you implement error response rate limiting -- i.e. don't feed
them the last line of the error response for at least 60 seconds or so,
then they can't "pound away", and certainly not several times a minute,
but rather will be restricted to making leisurely retries that don't
impact the performance of your other SMTP clients.
--
Greg A. Woods
+1 416 218-0098; <g.a.woods@???>; <woods@???>
Planix, Inc. <woods@???>; VE3TCP; Secrets of the Weird <woods@???>