When talking about autoresponder email software we usually mean a piece of software package you can install on your server that will give you the autpresonder functionality .
This software can be installed either on your computer itself, but in most cases nowadays, it's installed on your server (usually the one that hosts your site). This solution is better for people who want to have more control over their email lists, and to host them physically. Using this option, no 3rd party ever sees your lists, ann they are safe with you. The database that stores them is under your control and on your server, at all times.
Let's take a look at some of the advantages you have when you use an autoresponder software:

1. You host your lists on your server and no-one can touch them. There were a few cases with autoresponder companies that went out of business, taking the email lists with them If you host your own lists, this will never happen.

2. You are using your own IP with emailing your list. If you outsource your auto responder, in most cases you will share an IP with other people. If one of them happens to be a spammer, your IP may be blocked from emailing certain ISP's. This will effect your email's deliverability. But - if you host your own lists, use your own server and your own unique IP - this scenario will never happen.

3. No monthly fees - You will pay a one time fee for purchasing the software package. You will not have to pay a monthly fee, so the long term costs are usually lower.

All this doesn't mean using an autoresponer software doesn't have it's downsides. Let's take a look at the less glamorous:

1. If you're not technically inclined, you may be a little worried about the technical steps you need to take in order to install the software over on your server. This can be addressed quite easily because most vendors offer free installation foe their customers.

2. You may not want to mess with email deliverability, managing your list and maintaining it etc. Maybe you just want to leave it to the pro's and have minimal involvement with technical harassments and maintenance. In that case, a better solution for you is to outsource the whole thing by using an autoresponder service.

Making the right choice is important and will have long term effect on your business and the amount of work you will do with your website.

Want to know more about how to use a great auto responder software? Dean Taylor has the answers for you at http://www.followup-autoresponder-101.com.