CreateSend is an email newsletter software for sending professional email campaigns and is used by businesses needing reliable email delivery.

Bird is a highly trusted Email API and AI-native platform for sending and optimizing high-volume transactional and marketing emails at global scale.

Bird is a highly trusted, enterprise-grade Email API and delivery platform used by large businesses to send, optimize, and scale critical communications globally.

Pepipost (now Netcore) is a developer-first Email API service providing high deliverability, scalability, and AI-powered features for transactional and marketing emails.

EmailsDesk appears to be a service related to email infrastructure, likely an email sending or delivery platform, given the domain name.

SendGrid is the best email delivery service for transactional emails and is used by developers and marketers worldwide.