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Yeah, I do not have a gmail account so I am only blocking email from gmail accounts to end the spam from gmail accounts. Of course, this can happen from any such email provider like gmail ... though I rarely get spam from Hotmail, etc accounts.
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Blocking Gmail is a pretty extreme measure Charley. Many technical people in the business use Gmail almost exclusively, it's kind of the "in" thing to do, and many business people like myself, with their own domains, have given up on email packages, such as Thunderbird, due to Gmail's archiving feature, and the ability to alias their domain email directly from Gmail. It makes life a lot easier to archive, than to have separate files on every client. So, you may be missing a lot of very valid emails, by categorically blocking Gmail.
Though you don't have a Gmail account, for those that do, a person doesn't have to see the spam count if they don't want to. Either CustomizeGoogle, or Better Gmail 2 offer the option to block the spam count from showing. Then, as mentioned earlier in this thread, they disappear after 30 days. Frankly, I haven't looked at the spam folder in either of my Gmail accounts for a couple of years.