Funny timing here, I must say.
I have just made a sizable investment in an autoresponder script and had it installed. I am in the hosting business and have had clients ask about the service and I also am setting up some affiliate programs that will use an autoresponder.
What many here are talking about is what is called sending Broadcast email. This is one-time sending of things like newsletters, specials, etc. All of the AR sites and scripts include this, as well as what is actually the "sequential autoresponders" that send out a series of articles, courses, sales letters, etc. on a scheduled basis.
Like Brian, I too have several customer lists that I wanted to add at AWeber instead of GetResponse, but it was the same situation. Even though my lists are all purchasers within the last six months, they wanted to go through the verify routine.
I just didn't want to go there. I'm not spamming anyone, just communicating with members of my forum, who definitely opted in and customers who also are legitimate continuing contacts. Of course, they will have the option to leave, but only through my regular mailings, not asked beforehand by a third party.
It is true that you can do the broadcasts with phplist and other scripts. Been there, done that. But you are under the gun with your hosting provider, many of whom won't let you send a quantity of emails at all, or limit you to maybe 50 per hour. Truly a hit and miss kind of deal.
With my AR on it's own cpanel account, on my own server, I can make my own rules. There is no restriction on the number of emails. And within the AR script I can set a "burst rate" to where they go out in small bursts, rather than 10,000 instantly.
The reasons for this are twofold. First, there is no sense tying up the server just sending emails and second, many of the ISP's and email services judge an item to be spam if too many from the same sender hit their mailservers at the same time. So, sending out a thousand at a time, with 100 of them Yahoo addresses would cause Yahoo to cut them off at the pass.
By bursting them in small groups, even just seconds apart, they do not get read the same way by the incoming mail servers and will have a much better deliver-ability rate.
So, even though there are some "under $100" AR scripts available that anyone can install on their cpanel hosting account, the server owners often will stifle any potential use of the script. They are concerned about slowing down their servers and becoming a "spammer haven".
I can understand Brian's frustration. Part of the reason I bought the script I did was so I can offer an AR service to folks like Brian, at a price half of the "big boys". And I can also offer a one-time broadcast service or a low priced monthly broadcast service to others.