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

Right Inbox - Schedule Emails in Gmail To Be Sent Later

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

Recurrr - Send recurring emails

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

FollowUpThen - The simplest way to schedule an email reminder