Not getting ANY bounced messages

[Gary]

I send about 1,000 emails every few weeks (4.4.1 PRO). In the past, I've used my web host SMTP server and have always seen lots o' bounces and was just about to purge the multiple bounces from my master list.

BUT...This time I used my ISP's server (comcast) and so far (24 hours later) have not seen ANY bounces.

I've run my mailing list thru eMail Verifier and there are plenty of bad, looks bad, etc. addresses.

So why aren't I seeing bounced messages this time?

Or maybe I should be asking why was I getting so many bounced when I used my web host's server?

[Gary]

OK...

So I just sent a bogus Email via my web host server and Comcast's server. Got a bounce when sent via web host but not Comcast.