diff --git a/src/arguments.js b/src/arguments.js
index 208e92b..d9e4b80 100644
--- a/src/arguments.js
+++ b/src/arguments.js
@@ -206,8 +206,8 @@ function getOptions(options) {
     commandOptions.smtphost = options.smtphost || process.env[ENV_VAR.SMTP_HOST];
     commandOptions.smtpport = options.smtpport || process.env[ENV_VAR.SMTP_PORT];
     commandOptions.smtpsecure = options.smtpsecure || process.env[ENV_VAR.SMTP_SECURE];
-    commandOptions.smtpusername = options.smtpusername || process.env[ENV_VAR.USERNAME];
-    commandOptions.smtppassword = options.smtppassword || process.env[ENV_VAR.PASSWORD];
+    commandOptions.smtpusername = options.smtpusername || process.env[ENV_VAR.SMTP_USERNAME];
+    commandOptions.smtppassword = options.smtppassword || process.env[ENV_VAR.SMTP_PASSWORD];
 
     // Set email subject.
     commandOptions.subject = options.subject || process.env[ENV_VAR.EMAIL_SUBJECT];
@@ -241,4 +241,4 @@ function getHtml(text) {
 module.exports = {
     getCommandArguments,
     getEventArguments
-}
\ No newline at end of file
+}