I am installing Postfix on my unmanaged VPS hosting machine and I am doing it first time ever. I followed the installation manual on Ubuntu site and everything looks all right except one tiny thing: I can’t send email using Telnet. Here is the response: 421 4.3.0 collect: Cannot write ./dfnBA9gfVO030273 (bfcommit, uid=0, gid=111): No [...]