Navision SMTP Error

We encountered intermittent error in Navision related to SMTP Mail.

Troubleshooting steps:

1. In Windows Command, run nslookup
2. <smtp mail server name>.<company domain>. This is FQDN
3. Check if DNS Server is able to show the IP Address
4. If can't show the IP Address, try to add DNS Suffix in IPV4 and try to run Navision application again
5. If the problem persisted, try to ping <smtp mail server name> and if it's failed, most likely it's windows issue (guess...)

Resolution :
--> Change SMTP Mail Server name in Navision SMTP Mail Setup to IP address.

After quite long break.....