A client of mine sends out 100,000-300,000 press releases per month to media and industry contacts. We have a Cloud server with 4GB RAM and an IP dedicated to sending the campaign emails with SPF, RDNS, DomainKeys, etc. We currently use ActiveCampaign PHP software to manage the 100 lists and 10,000+ subscribers. We send out emails everyday, sometimes a few campaigns per day. The software we use seems to be very slow at sending and brings our service to a halt at times, but the RAM & CPU is not overloaded at all.

Is there a better web based software package to use?

Or a Win PC Based software that can handle the email creation, subscriber management and sending by SMTP?

The client used to use mailman but that was a nightmare to create lists and manage subscribers.

Click tracking/read tracking is needed.

We also have the wordpress based web site on the same server, would it be best to setup the email list system on a separate server?

The client looked into mailchimp, constant contact, icontact, etc but all were far too expensive for the volume they send.

Advice appreciated. Thanks!