Hello,
I have two proposal one in trendy means having a server and sends millions of email with low inboxing and other is sending emails through gmail, hotmail, aol and yahoo. You see the idea behind this is send limited but with 100% inboxing. How we are going to do it let me define you.
1) We create multiple ids where id is either sequential or random but same name appears on the inbox. e.g. 10 gmail ids.
2) We Mail merge with the client id and send 1 by one till the daily sending limit per id reached
3) we will setup autoforwarding to one master email which will collects all the reply so that you can check and reply them accordingly
after ever id ip will be switched and cache would be clean so no blocking can be accord.
I hope you like my idea and give us a chance thanks.
Regards