One thing you can do is change the packet size for each delivery.  If the packet size is
50, try to up it to 75 or 100.  This can be done via the sendmail.cf file.

> I'm looking for some advice on tunning up sendmail for delivery of
> Listserv HPO version. I have the following lists, and the time for
> each mailing:
>
>
> Any sendmail tips tricks or suggestions are welcome.
>
>
> Thanks,
> Dennis
>
>
> > HotdealSHTML  (51,944 recipients) Start 12:19:23 Finish 15:55:36
> > Time: 3hrs or so
> >
> > MBRHTDEALHTML (46,706 recipients) Start 15:55:38 Finish 18:51:32
> > Time: 3 hours or so
> >
> > HOTDEALSTXT (181,194 recipients) Start 18:51:36 Finish 07:19:50
> > Time: 13 hours or so
> >
> > MBRHTDEALSTXT(21,714 recipients) Start 7:19:55 Finish 8:26:55 Time:
> > 1 Hour or so
> >
> > Total: 20 hours for a mailing.
> >