Proxmox Mail Gateway - Protect mail server against spam, viruses and malware with Proxmox Mail Gateway security for businesses, government, education and non-profit organizations.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Rspamd - Rspamd is an advanced spam filtering system that allows evaluation of messages by a number of rules...
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
SpamAssassin - Use this program to "Unspam" your mailbox(es).
Plivo - Plivo simplifies your customer engagement.