Hi,
The correcht email software depends by:
1. how many emails you have to send.
2. in wich period of time.
3. what budget you have.
I can recommend a 40 usd per month sollution:
A vps having 2 ips, 700MB RAM, 1.1 Mhz Proc, 30 GB RAM, 1TB bandwidht having instaled phplist (phplist will handle bounces, unsubscribe, click track, email opens track).
ALos the server will require to set up DKIM, DOmaninKeys, SPF records, RDNS.
This configuration will make possible to send out 20.000 emails per day.
THis is a tested sollution for 1 year by me.
If you want to send 100.000 - 150.000 emails per day, you will need a 140 USD monthly investment in a dedicated server.
THe software is phplist. but it require a server to access a smtp server which will send emails.
This are realistic sollutions, don't waist your time with desktop applications because on those you will have to buy the application and also you will need a smtp server to send out emails.
I will require 200 USD for:
1. Configure the server (DKIM, DomainKeys, SPF records, RDNS).
2. Check the ip-addresses if they initially are in spam lists, and require other IP if necessary.
3. Instal and configure phplist
4. import your database.
5. test aplication.
6. make our first email campaign and learn you how to use it in the feature.
Thanks!