EDIT: Eu não estou familiarizado com a execução de comandos do Cygwin a partir de um arquivo de lote que eu vi referência a ele em outro lugar. Dependendo da sua experiência com o Cygwin, uma das outras respostas talvez seja mais adequada às suas necessidades, mas deixarei essa aqui para a posteridade.
Se você já tiver o Cygwin instalado, poderá instalar o pacote email
.
$ email --help
Options information is as follows
email [options] recipient1,recipient2,...
-h, -help module Print this message or specify one of the below options
-V, -verbose Display mailing progress.
-f, -from-addr Senders mail address
-n, -from-name Senders name
-b, -blank-mail Allows you to send a blank email
-e, -encrypt Encrypt the e-mail for first recipient before sending
-s, -subject subject Subject of message
-r, -smtp-server server Specify a temporary SMTP server for sending
-p, -smtp-port port Specify the SMTP port to connect to
-a, -attach file Attach file and base64 encode
-c, -conf-file file Path to non-default configuration file
-t, -check-config Simply parse the email.conf file for errors
-x, -timeout Set socket timeout.
-cc email,email,... Copy recipients
-bcc email,email,... Blind Copy recipients
-sign Sign the email with GPG
-html Send message in HTML format ( Make your own HTML! )
-tls Use TLS/SSL
-m, -smtp-auth type Set the SMTP AUTH type (plain or login)
-u, -smtp-user username Specify your username for SMTP AUTH
-i, -smtp-pass password Specify your password for SMTP AUTH
-g, -gpg-pass Specify your password for GPG
-H, -header string Add header (can be used multiple times)
-high-priority Send the email with high priority
-no-encoding Don't use UTF-8 encoding