Recently, I was asked a question regarding autoresponders. My response turned out to be a bit detailed and I thought many people could benefit from it. You can read it below (between asterisks).
"What is the benefit of List Wire vs. one of the WP autoresponder apps?"
I haven't used WordPress autoresponder plugins, so I cannot give an opinion on them. I installed one with a lot of advanced features, but I never put it to use.
The Biggest Downside to Hosting Your Own:
Many people will mark your messages as spam, instead of unsubscribing. Others will mark your messages as spam because they forgot that they subscribed. Over time, your I.P. address will end up on several email blacklists and your messages will stop being delivered altogether. And, from my own experience, I can attest to how hard it is to get off of some of these blacklists. Some of them are so uneducated that they will not remove you under any circumstances (i.e. the 'if you send email, you are a spammer' mentallity).
The Biggest Upside to Hosting Your Own:
You have 100% control over all aspects of the entire system.
As for any direct sales customers you have —for example, if you provide any kind of service— I recommend either of these two options:
A. Host your own autoresponder and have your service contacts and other paying customers sign up to that.
B. Send your service contacts and paying customers to a third-party autoresponder service, but have them automatically added to a database on your own host for back-up.
What Do I Use?
I use List Wire for "Internet marketing" subscribers and VerticalResponse for service leads and customers. I am currently creating a system that I will host on my own domain, in addition to these third-party services.
I hope this is of use to you, as you ponder different autoresponder options. There is no perfect autoresponder. They all have different features and the subscribe and unsubscribe processes work differently from one responder to the next, be it a third-party autoresponder service or an autoresponder script that you install on your own host.
For example, List Wire has fixed intermediate pages (confirmation instructions…), follow-up messages and a cooperative registration ("co-reg") system. VerticalResponse allows you to choose between VR-hosted pop-ups or your own custom intermediate pages, but they do not have follow-ups or co-reg. (VerticalResponse was recently aquired by a larger company. Perhaps we'll see follow-ups in the future.)