Clean Email - Clean Email is an online service that empowers you to take control of your mailbox.
Hornetsecurity - Hornetsecurity offers you comprehensive, integrated managed e-mail security services.
MailClark - The Slack bot for external communications
Mimecast Gateway - Mimecast Gateway is a SaaS-based email security solution that uses sophisticated, multi-layered detection engines and intelligence to protect email data and employees from malware, spam, advanced threats and zero-day attacks.
Hiver - Manage Customer Support, Sales and Projects right from your Gmail inbox. Collaborate with Shared Labels, Shared Contacts, email notes, email reminders and email templates
dmarcian - Safeguard your email from abuse