Hello everyone, we have 3 or 4 company emails that are getting 300 to 400 spam mails every single day. The funny thing is that we have over 50 email addresses under the same domain, but only 3 or 4 are getting this much spam.
The problem started when we went from Linux to a Windows dedicated server, now after hacing all this spam issues, we switched back to Linux but we stil have the same problem with the spam.
Can anyone please provide suggestions, tips, or things we check or do on the linux server to protect and fight all this spam?
Also, what caused these 3 or 4 addresses to get this much spam all of a sudden?