In the interests of cost saving I am thinking to cancel my auto-responder subscription. You must use a web server for an autoresponder (so that it may immediately respond to a new subscriber), but due to sending restrictions and the risk of spam complaints, most people don't use their own web hosting account for this, but pay a provider on a monthly basis.
My plan with the home-based server is to code a server-side script to send e-mails via gmail. This should be simple to code since there are cut and paste code examples for how to send email readily available. So instead of a PHP or PERL script, I may code it in C# dot net.
For the actual email list management I will use an application called SendBlaster. This can download emails and send them, but handles all of the management such as detecting bounces, and broadcasting emails to lists.
I thought about setting up a mail server but decided against it in case I upset my ISP where I am not paying for a business account.
For email list management you could also use PHP List, Outlook, or Mozilla Fire Bird etc. And for the autoresponder, you could use a PHP script to drive these packages from the command line maybe (with command line directives)?
This is all aimed at removing another monthly fee from the web marketing budget.