The process of preparing an email address for general use or email outreach is commonly referred to as “Warming Up” an inbox, where you take a number of steps to ensure that an email address does not become deactivated, blacklisted, or automatically marked as spam when it begins to send outgoing messages to other recipients.

Warming Up an email inbox essentially is recreating the way a typical person will use an email address. Just by using your email address normally, you are ‘warming up’ your inbox by sending outgoing mail to other existing users. When you are reading your emails, starring/favoriting certain messages, and engaging in email threads with multiple other email addresses, you are building up your domain reputation in a way that shows that your account is being controlled by a real human being and is not being used to send out unsolicited emails that are trying to mislead/scam/defraud any other real people using their email inbox.

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.