Send newsletters in batches?

Maybe this has already been covered elsewhere, but has anyone tried modifying the code that sends newsletters to have it send in batches with a waiting period in between? I'd be interested in tinkering with this but am not sure where to get started.

I'm sure many people run into the email host limiting outgoing emails to a certain number within a given period.

Any ideas? In the meantime, looks like my client will need to simply export the newsletter subscribers and send through a separate program (in this case GroupMail).

The bulk mailer at epishire.com is written for Zen Cart and will send out emails from the newsletter manager at 1 per 8 seconds.

seacindy:

The bulk mailer at epishire.com is written for Zen Cart and will send out emails from the newsletter manager at 1 per 8 seconds.
Program/mod offered does not appear to be FREE..

No, unfortunately, not free.