[Mailman-Users] Undelivered Mail Returned to Sender

[John Levine]

In article <20180804141855.7510026C1F29 at sharky3.deepsoft.com> you write:
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>
>Do you have access to your inbound mail server? If so, you need to arrange for
>that server to *reject* all mail connections from qq.com. qq.com is a
>*notorious* source of spam (there are no legitimate E-Mail addresses @qq.com).
>You might also want to firewall Chinese IP addresses as well.

Actually, there are millions of legitimate e-mail addrsses at qq.com.
It's Tencent, the giant Chinese company that owns Wechat, which has
900 million active users, all with an e-mail address linked to their
Wechat accounts.

Nearly all of the users are in China, so if you don't expect anyone
from China to subscribe to your lists, I suppose you can block them.