Thanks. It's a persistant connection to localhost (actually I restart every 1000 emails). The linux server is a dual p3 1.1Ghz with 4G ram. We have two solaris, one quad 450 4G, and a dual 450 with 2G ram. The Net::SMTP performance is similar on the both. I think I may have figured out the difference in performance, the solaris server(s) are on an EMC array, while the linux is off localdisk. The performance is pretty good on linux if I send a single mail to tons of recipients, but not one mail per recipient. I need to be able to send in both ways. I guess the localdisk may explain that.