Autoresponder

I have a lead business where customers buy 100 to 10,000 leads at a time from me. I post their leads in a .csv file in their back office that has a unique username and password. Here is an example if you were a customer: [login to view URL] Username:? ? 2278 Password:? ? demo When you go there click on "Autoresponder" and you will see it is under maintenance. What I need there is the following: 1)? The ability to import ONLY the leads that are located in their members back office under the link called "Leads".? I do NOT want them to be able to import any leads on their own.? They can only email leads they buy from us that are posted in their back office. 2)? The ability for the member to do a one time broadcast, or to import a series of text letters (no .html needed unless you can convince me why we need to have both options for letters). 3)? The ability for each member to click a set of their leads and email them once at a time, or all at once. This brings up a big issue. I had someone program this before but all the leads from each user were trying? to go out all at once and it crashed the server all the time and we also got blacklisted due to thousands of emails trying to go to AOL and MSN at once. So, I need someone to program this in a que where if you and I are wanting to send emails, the autoresponder only sends out one account at a time and we are all in "line" so to speak.? First come first serve when it comes to sending out emails and not all of them trying to go out at once. Any questions, let me know. Robert