SendGrid

Scalable email delivery for apps that actually send a lot of email.

Best use cases
Transactional emails
Marketing campaigns
Password resets
Notification emails
Email analytics
Pros
Highly scalable infrastructure
Strong deliverability
Detailed email analytics
Flexible APIs and SMTP support
Widely adopted
Cons
UI can feel cluttered
Pricing jumps with volume
Support quality varies by plan
Pricing
freemium
Free tier available + paid plans based on email volume
Alternatives