I am setting up an ISPConfig3 system to replace a manually-configured Postfix/Courier system for ISP-style e-mail access. My ISPConfig install went quite smoothly, but I am left with one problematic issue. ISPConfig e-mail boxes need to be logged into with a email@example.com style address, but this particular box (will only be serving one domain) needs to accept username-only (with appropriate-password, of course) logins for IMAP and POP. Has anyone run into this before (seems likely to me), and is there any configuration advice on this? Any and all input is greatly appreciated. Thanks!