Interspire has managed a reputation of market leader software, when it comes to setup self-hosted email marketing environment. Combination of Interspire with VMTA based PowerMTA has long been rated the first choice for self-hosted email infrastructure. Interspire somehow stopped further development; they also tried BigResponse but stopped accepting new signups. Some third party developers programmed several custom addons for Interspire and enhanced the capabilities of the platform. Some of the value added modules are in the following links, by third party developers for Interspire. https://www.maborak.com/interspire/addons/multiple-mta-with-ip-monitor.html https://www.maborak.com/interspire/addons/powermta-remote-bounce-processor.html http://www.interspiremods.net/iem-engine-features.php I?ve tried to list few of the alternatives of Interspire MailWizz ----------- MailWizz offers all basic functionality and features in affordable price. The software is suitable for startups and small size senders, who don?t want extensive customizations and long list of features. The main attraction of MailWizz is its affordable pricing. They are way to inexpensive compared to other standalone email marketing application. Check the complete features here... http://www.mailwizz.com/ Mumara ----------- The nearest alternative to Interspire, with long list of features and custom addons, ability to select custom sending patterns, enhanced capability to work with PowerMTA server, improved speed with ability to execute parallel sending activity, Multi MTA, ability to keep SMTP connection persistent for sending, as well as sending in a loop sequence by keeping SMTP connection non-persistent. The main charm of Mumara is its long list of features, 20+ custom addons, and its ability to work with PowerMTA server effortlessly. More details are in the following links https://www.mumara.com https://www.mumara.com/addons/ Sendy ----------- Sendy also offers an affordable way to send emails using Amazon SES. Also for the Sendy, its main charm is its affordability. You can notice the price comparison meter they have advertised on their website that compares their per email cost with MailChimp and Campaign Monitor. There is certainly difference of pricing, but difference of features and solutions as well, for example, Sendy lacks Split Testing ability, and such other features. Amazon SES is strict in its measures to ensure permission based emailing and curb email spam. Sendy doesn?t have any long list of features to offer, though all of the basic functionality is covered. Here is the website https://sendy.co/ ExpertSender --------------------- There is another comprehensive email marketing application offered by ExpertSender. They have managed a good list of features for advance segmentation, personalized and dynamic content, detailed reporting and analytics and much more. They also claim expert level support for delivery optimization. Their pricing model isn?t clear, as far I know they deploy their system on demand. Both ExpertSender and Mumara have capabilities to assist enterprise companies and ESP setups also. More information on expert sender can be found on their website. http://www.expertsender.com/ There are some other solutions like www.arpreach.com and Active Campaign was also one amongst the list of licensed email marketing software. But they have discontinued and this particular edition of ActiveCampaign is no longer available for public. What other software do you know?