EmailOctopus - Email marketing for less, via Amazon SES
SE Ranking - All-in-One cloud-based SEO software for agencies, marketing teams and webmasters
MailChimp - MailChimp is the best way to design, send, and share email newsletters.
DeskAlerts - Send alerts to any corporate device: PCs, phones, tablets, etc.
.meteoremails - Send cold emails for free! Free and open source project
SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.