Sometimes Smart Email Verifier does not properly detect the system setting, or doesn't work with your Internet Service Provider's DNS.
To resolve this problem:
1. Click Tools >> Options.
2. Switch to the DNS tab.
3. Click "Let me specify one or more DNS servers"
4. For the Preferred DNS Server, enter the address of a public DNS server known
to work with Smart Email Verifier: 199.166.31.3
5. For the Alternate DNS, enter: 66.93.87.2
6. Click OK.
You will now be able to use Smart Email Verifier.