How to block or blacklist emails from all subdomains of a blocked domain?
I have blocked emails from entire domains (by blacklisting like @domain.tld), and they work fine usually.
However, some spam domains use subdomains to send spam, and they keep changing subdomains so blocking/blacklisting them becomes difficult.
For e.g. @sweretgo.ru is blocked, even @s2.sweretgo.ru is blocked, but then I notice they are sending spam from s3.sweretgo.ru and s7.sweretgo.ru subdomains.
Should @sweretgo.ru being blacklisted not block all emails from that domain (including its subdomains)?
If not, and if it is intended behaviour, then what is the way to achieve that? Because a wildcard didn't work - I tried adding @*.sweretgo.ru to Block/Blacklisting and Mailbox settings portal threw an error:
Error: The value of the 'email' parameter does not appear to be an e-mail address