Mailook - Identify & fix your email deliverability issues for free 👀

Marketo - Marketo's powerful marketing automation software helps marketers master the art & science of digital marketing to engage customers and prospects.

Sidemail - The simplest way to send transactional emails. Sidemail makes sending transactional emails trivial, it's perfect for side projects, MVPs or the next big thing.

Constant Contact - Constant Contact offers email marketing, social media marketing, online survey, event marketing, digital storefronts, and local deals tools.

Mailivery - Reach the Inbox, not the spam folder.

Omnisend - Omnisend - Marketing Automation for Ecommerce provides the omnichannel approach for sales-driven marketers that have outgrown the generic email marketing platforms.