Is this address “support@sol-bd.com” a local address at the email server in “/tools e-mail”? Or will it need to be forwarded to another email server for delivery?
That is called a relay. Does the email server you have entered allow relaying from the ip address of your router?
ADD: The best way is to use the ip of the email server that handles the email (has the email account) for support@sol-bd.com. Your dns record (nslookup) shows that you do have an email exchange for that domain.