What are some alternatives?
When comparing Flexmail Solution and ListShine, you can also consider the following products
MailChimp - MailChimp is the best way to design, send, and share email newsletters.
1and1Mail - 1and1Mail is a free email marketing software to send out mass email campaigns, manage email contacts and design email newsletters for small and medium business.
SendPulse - Maximizing e-mail marketing open rates automatically
GetResponse - Email marketing from GetResponse. Send email newsletters, campaigns, online surveys and follow-up autoresponders. Simple, easy interface. FREE sign up.
Sendy - Sendy is a self hosted newsletter app that sends emails 100x cheaper via Amazon SES
shiftmail - Email analytics made simple. shiftmail provides a REST API and web interface for intelligence gathering within email marketing.