One-line SMTP send with curl

ezmail.sh

#!/bin/bash

# Sends an email with the params:
# - CURL_SMTP_SERVER: SMTP server URL in the form of 'smtp(s)://host:port'
# - CURL_SMTP_FROM: the sender e-mail address
# - CURL_SMTP_TO: the recipient e-mail address
# - CURL_SMTP_USER: the SMTP user (optional)
# - CURL_SMTP_PASSWD: the SMTP user's password (optional — ignored if CURL_SMTP_USER is empty)
#
# Usage:
#   ./ezmail.sh subject [body]
#   (if no body, reads from stdin)

curl -sS \
  --url $CURL_SMTP_SERVER \
  --mail-from $CURL_SMTP_FROM \
  --mail-rcpt $CURL_SMTP_TO \
  $(test -n ${CURL_SMTP_USER-''} && echo -ne '--user '$CURL_SMTP_USER':' && test -n ${CURL_SMTP_PASSWD-''} && echo -ne $CURL_SMTP_PASSWD) \
  -T <(echo -e 'From: '$CURL_SMTP_FROM'\nTo: '$CURL_SMTP_TO'\nSubject: '$1'\n\n'${2:-/dev/stdin})