I am new to email servers with Smartermail 13 and have set up Smartermail using the ChicagoNet suggestions. Checking my SMTP logs I was seeing my own IP (webserver and email on the same IP) trying to authenticate live email addresses. Checking the ids block I also find my own IP indicated as DOS and Brute Force.
I have checked the Online Users in User Activity and I find IP's from China and me as system admin. I don't have any Chinese users, in fact there are only 36 users in total. The IP my be spoofed from Baidu the Chinese search engine so I have blacklisted their entire IP range as a trial.
Initially the server SMTP logs showed thousands of rejections which were blacklisted so I thought I had resolved the issue. Now I am not so sure as checking the IDS Blocks I find my IP address in there again.