--- a/mailnews/compose/src/nsSmtpProtocol.cpp
+++ b/mailnews/compose/src/nsSmtpProtocol.cpp
@@ -1512,17 +1512,17 @@ nsresult nsSmtpProtocol::AuthLoginStep1(
     char plain_string[512];
     int len = 1; /* first <NUL> char */
 
     memset(plain_string, 0, 512);
     PR_snprintf(&plain_string[1], 510, "%s", username.get());
     len += username.Length();
     len++; /* second <NUL> char */
     PR_snprintf(&plain_string[len], 511-len, "%s", uniPassword.get());
-    len += password.Length();
+    len += uniPassword.Length();
 
     base64Str = PL_Base64Encode(plain_string, len, nullptr);
     PR_snprintf(buffer, sizeof(buffer), "AUTH PLAIN %.256s" CRLF, base64Str);
   }
   else if (m_currentAuthMethod == SMTP_AUTH_LOGIN_ENABLED)
   {
     MOZ_LOG(SMTPLogModule, mozilla::LogLevel::Debug, ("LOGIN auth"));
     base64Str = PL_Base64Encode(username.get(),