The Postmark Ruby SDK by Wildbit allows API interaction with the aim to send emails and provide statistics for service improvement. References for implementation explain how to install with gem, get an Api token, and communicate with the API. Code shows how to send an email message, send an HTML message, and send attachments.
SparkPost announced a version of its SparkPost API that is fully compliant with the upcoming GDPR in the EU. SparkPost EU is hosted in Europe as opposed the the US where the original API is hosted. The EU version brings compliancy as well as lower latency and increased performance to EU customers.
Mailgun added a slew of new features to its email validation API including target mailbox validation, role-based address check, disposable mailbox, reporting, and rate limits. Additionally, Mailgun added the API under its existing SLA and has transitioned to a tiered, usage-based pricing model.