Originally Posted by Infusionsoft
Every company has their own benefits but I would take a few things into consideration when selecting a software:
1. Deliverability percentage because this will help your emails get sent instead of bounced.
Rather than this being a reflection on the email software used, the percentage depends more on the quality of your subscriber list, the subject line used, whether your sending domain name is verified (with domain keys), and whether content is spammy.
Hope that helps.