CMail VS Zimbra

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.

Features

• Flexible configuration via files or the command line and optional GUI provided by CMailGUI.
• TLS/SSL (including TLS 1.3) via STARTTLS or SMTPS (SSL-enabled version). Built-in, stunnel not required.
• Support for adding multipart/alternative HTML message bodies (UTF-8) and embedded images.
• SMTP authentication using CRAM-MD5, PLAIN, LOGIN, OAUTHBEARER and XOAUTH2.
• Unlimited attachments using base64, quoted printable or uuencoding.
• Wildcard attachment support to attach directory content.
• Unlimited To/Cc/Bcc recipients, with aliases and DSN options for each if desired.
• Message bodies using plain text, base64, or quoted printable encoding.
• IPv6 support.
• DKIM signing (RSA and Ed25519).
• Delivery Status Notification and Message Disposition Notification (Read receipt) support.
• Read message body from command line, stdin or file.
• Sending via SOCKS or HTTPS proxies.
• Works with GMail using App Passwords or user-supplied OAUTHBEARER/XOAUTH2 tokens.
• Written entirely in C - no need for .NET libraries, Java, or other prerequisites.
• No installation required. Download, extract, use.
• Free for private and commercial use.

Zimbra is the trusted email and collaboration platform and productivity suite that includes contacts, calendar, tasks, chat and file sharing, plus videoconferencing, document editing, and file storage. Built on an open source core, it features a modern interface, pre-integrations with popular third-party apps like Zoom, Slack and Dropbox, and can be deployed in the cloud or in on-prem and hybrid environments. Enterprises, governments, financial institutions, service providers and remote teams around the world rely on Zimbra to support complex privacy, data sovereignty and security requirements. Today, Zimbra powers hundreds of millions of mailboxes on desktop and mobile devices in more than 140 countries, and is offered by more than 500 BSPs and 2,000 channel partners. Also available now for small and medium-sized business is Zimbra Cloud, starting at $2.95 per month for 30 GB of storage. Visit www.zimbra.com to learn more and begin a free trial.