Re: [CentOS] Per-user limits for port access

Jussi Hirvi wrote:

Is there a way to limit port access on a per-user basis? My practical goal is to limit, who is allowed to use SMTP AUTH in Sendmail. Any possible solutions appreciated...

Obviously, limiting by ip will not work, since the very purpose of SMTP AUTH is to enable mail relaying for trusted users from *anywhere*.

You could use new ability of milter-greylist (from 4.0 version), that provides method to limit connections by any criteria, such as remote ip, sender/recipient address, authentication status and many more. You could extend configuration by using external helper, that can be reached by, for example, ldap or http protocols.