Klaviyo
klaviyo.com
Email and SMS built around e-commerce data
from $20/moFree plan
SendGrid
High-volume email infrastructure
Free plan availableEmail MarketingSince 2009
from $20/moVisit sendgrid.com
What SendGrid is
Twilio-owned sending platform covering both transactional API traffic and marketing campaigns, built for large volumes and dedicated IP setups.
People use it to
Current offers
Free plan
Free plan, no card required
Ongoing free tier published by the vendor. Limits vary by plan.
SendGrid alternatives
Other tools in email marketing that cover similar ground. Full comparison.