Do you really send out more than 20 emails a minute? Are they legitimate
emails or spam? I'm having trouble picturing a need to send more than 20
emails a minute unless you are a spammer, in which case I certainly wouldn't
help you because there is already too much spam in the world.

Rhino

I just switched IAPs and they are blocking my SMTP access to my
mailserver hosted by a different ISP.

See http://mindprod.com/joloss/iap.html
http://mindprod.com/jgloss/isp.htm
if you are not familiar with those terms.

Here are two ways to get around them stopping your from using someone
else's mail server.

1. Set up your mailserver to accept some other port besides 25. This
mailserver cannot live in the IAP with blocks since it in turn would
be blocked from distributing mail to port 25 on other machines.

2. Run your Java program on some other host on a "Spam-friendly iap".
FTP your list to it, and let it rip.

I wrote a program called the Bulk Emailer that used Javamail to send
bulk emails.  It does a lot of checking of addresses to avoid swamping
the sender with bounces.  One problem I ran into was email hosts that
limited the size of each JavaMail batch and also the total number of
emails you could send per day.  The per day limit was a bear.  The
main reason the charities got me to write the program was Eudora had a
fairly low limit on thi size of its email batches.

You can get around some limits running your own local mail server, but
then you bang into their port 25 blocking.

See http://mindprod.com/products1.html#BULK