MailGenius is described as 'Free Email Spam Checker & Testing Tool' and is a Email Marketing service in the business & commerce category. There are three alternatives to MailGenius for a variety of platforms, including Online / Web-based, SaaS, Windows, Chrome OS and Linux. The best alternative is Maildog.co. Other great apps like MailGenius are GlockApps and Vetter.
GlockApps provides everything you need to help troubleshoot and monitor inbox placement, email reputation, and campaign performance so that you can adjust your strategic and tactical plans, improve results and increase ROI.
Vetter allows you to safely determine whether an email you wish to send will be marked as spam. This is done by testing the email against a network of real email accounts, and checking whether it ended up in inboxes or was spammed.