Earlier today, I started getting a large number of emails about blocked distributed smtpauth attacks on my email account.
I was unable to authenticate and my IP ended up being blocked too, even though I was using the correct password.
I've implemented SMTPAUTH_RESTRICT as per the instructions in the CSF readme.txt, and also set CC_ALLOW_SMTPAUTH to only allow connections from GB.
Rather than rebooting my router for a new IP, I'm currently waiting for my temp block to expire, but want to know if I need to add anything to /etc/csf/csf.smtpauth or /etc/exim.smtpauth. As my IP address changes, I ideally would like all GB IP's to be allowed to authenticate.
SMTPAUTH_RESTRICT
Re: SMTPAUTH_RESTRICT
I logged into the server once my block was done, and see that all the possible GB IP's were automatically added.