A 'DumbDomain' is what I call a mail server that'll accept any address and process it internally against existing accounts, rather than rejecting the validation request outright if the account doesn't exist. That's why you see NDRs (non-delivery reports) for bad accounts sometimes coming from your ISP, and sometimes from the mail server at the target domain.

It's why you see this address being created in the DumbDomains() method:

lcEmail = SUBSTR(SYS(2015),2)+SYS(2015))+"@"+tcDomain

The odds of this account actually existing on any given mail server is probably about a trillion to one.

If the mail server for that domain replies with a 3 (valid address), you can pretty well count on it being a 'DumbDomain,' and once you've determined this you won't want to validate other addresses on your list against that mail server.

It speeds things up significantly.




>Thanks Jeff
>
>BTH what does dumdomains contain. I have put 3 emails in - 2 are correct (1 of them is a hotmail address) - dumbdomains only shows the other correct email address.
>
>Colin