Fix processing of allow system smtp settings flag

application/src/main/java/org/thingsboard/server/actors/ruleChain/DefaultTbContext.java

@@ -525,8 +525,8 @@ class DefaultTbContext implements TbContext {
     }
 
     @Override
-    public MailService getMailService() {
+    public MailService getMailService(boolean isSystem) {
-        if (mainCtx.isAllowSystemMailService()) {
+        if (!isSystem || mainCtx.isAllowSystemMailService()) {
             return mainCtx.getMailService();
         } else {
             throw new RuntimeException("Access to System Mail Service is forbidden!");

rule-engine/rule-engine-api/src/main/java/org/thingsboard/rule/engine/api/TbContext.java

@@ -231,7 +231,7 @@ public interface TbContext {
 
     ListeningExecutor getExternalCallExecutor();
 
-    MailService getMailService();
+    MailService getMailService(boolean isSystem);
 
     SmsService getSmsService();
 

rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mail/TbSendEmailNode.java

@@ -86,9 +86,9 @@ public class TbSendEmailNode implements TbNode {
 
     private void sendEmail(TbContext ctx, TbMsg msg, TbEmail email) throws Exception {
         if (this.config.isUseSystemSmtpSettings()) {
-            ctx.getMailService().send(ctx.getTenantId(), msg.getCustomerId(), email);
+            ctx.getMailService(true).send(ctx.getTenantId(), msg.getCustomerId(), email);
         } else {
-            ctx.getMailService().send(ctx.getTenantId(), msg.getCustomerId(), email, this.mailSender);
+            ctx.getMailService(false).send(ctx.getTenantId(), msg.getCustomerId(), email, this.mailSender);
         }
     }