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Re: Need advice on large mailing lists
> does chunking affect the to: or from: lines or the header in any way?
The rfc822 headers are unchanged. Chunking simply groups the SMTP
recipients in one message into several SMTP messages.
If you use a mailing list manager such as Listserv[tm] or Listproc then it
already chunks. See the Mailing List Manager (MLM) FAQ at
We use Listserv[tm] with Zmailer on another machine and had to turn down
the number of addresses it grouped to because it blew up the router.
> Does the router do one DNS lookup once per message in that case?
We turn off router DNS lookups. On international mailing lists we find that
many times about 10% of the lookups time out or nearly time out. (With
"ordinary" email we consistently see less than 1% of DNS lookups time out.)
Even if you turn down the length of time to timeout, on international
mailing lists this can be significant.
University of Toronto