dkim

CMail is a command line e-mail sending tool. It was originally developed to assist with testing mail server and content analysis software. As a result, CMail provides many more message formatting and SMTP session control options than similar software.

Full featured solution for your Email server. Native implementation of last anti-SPAM metods, webmail and easy administration included.

Scalable email delivery for transactional emailSendGrid transparently handles DKIM, SPF, ISP rate limits, content inspection, bounces, and spam reports to help users achieve higher deliverability. SendGrid integrates in minutes by just changing three SMTP settings.