Adding SendRaven

SendRaven provides an email API for transactional email and agent-driven conversations, including inbound replies and threads. The free tier includes 3,000 outbound emails per month, unlimited contacts and inbound replies, card is required.

README.md

@@ -928,6 +928,7 @@ This list results from Pull Requests, reviews, ideas, and work done by 1600+ peo
   * [SendBridge Mail Tester](https://sendbridge.com/mail-tester) — Free email deliverability test with no signup. Generates a unique inbox address, then analyzes SPF, DKIM, DMARC, Rspamd spam score, 23+ RBL blacklists, reverse DNS, and content quality. Unlimited tests, results in seconds, shareable report pages.
   * [Sender](https://www.sender.net) - Up to 15,000 emails/month, up to 2,500 subscribers
   * [Sendpulse](https://sendpulse.com) - 500 subscribers/month, 15,000 emails/month free
+  * [SendRaven](https://sendraven.ai) - SendRaven provides an email API for transactional email and agent-driven conversations, including inbound replies and threads. The free tier includes 3,000 outbound emails per month, unlimited contacts and inbound replies, card is required.
   * [SendStreak](https://www.sendstreak.com/) - Email framework as a service, that adds templates, automations, history, etc to your own SMTP server (E.g. AWS, Maileroo, Gmail). Free up to 100 emails/day, no time limit.
   * [SimpleLogin](https://simplelogin.io/) - Open source, self-hostable email alias/forwarding solution. Free 10 Aliases, unlimited bandwidth, unlimited reply/send. Free for educational staff (student, researcher, etc.).
   * [SMTPfast](https://smtpfa.st/) - SMTPfast is a simple email API for developers with a free tier that includes 3,000 emails/month, 1 domain, and 1,000 contacts, with no credit card required.