Hi, I installed ISPConfig 3 on Fedora 12 32bit. I used for that the "Perfect Guide" for Fedora x86_64 (thank you Falko!). I setup 2 mail domains easily and everything seems to work just fine, so far. After I tried with no luck to search the Postfix documentation,this forum and google I still have an issue to deal with. I couldn't find anyone with this problem yet (I hope I'm not wrong) , but here it is: With SMTP auth on, only verified users cand send mail through my server - which is good; the thing is on the client application I can write at Identity/Email Addres ANY email I want (e.g. [email protected]) as long the username for the smtp auth remains [email protected] . The server sends the email like it was from [email protected] not the actual [email protected] who logged in. I guess there is something wrong with my MTA configuration because this behavior enables any user to impersonate anyone, as long as they know his/hers email address. I expected that mysql-virtual_sender.cf declared in main.cf to help me, but it points to an empty table (mail_access). So, the questions are: This is an issue? and How can be corrected? Here is my main.cf, if it helps. (I removed the first comment lines): Code: #soft_bounce = no # LOCAL PATHNAME INFORMATION # # The queue_directory specifies the location of the Postfix queue. # This is also the root directory of Postfix daemons that run chrooted. # See the files in examples/chroot-setup for setting up Postfix chroot # environments on different UNIX systems. # queue_directory = /var/spool/postfix # The command_directory parameter specifies the location of all # postXXX commands. # command_directory = /usr/sbin # The daemon_directory parameter specifies the location of all Postfix # daemon programs (i.e. programs listed in the master.cf file). This # directory must be owned by root. # daemon_directory = /usr/libexec/postfix # The data_directory parameter specifies the location of Postfix-writable # data files (caches, random numbers). This directory must be owned # by the mail_owner account (see below). # data_directory = /var/lib/postfix # QUEUE AND PROCESS OWNERSHIP # # The mail_owner parameter specifies the owner of the Postfix queue # and of most Postfix daemon processes. Specify the name of a user # account THAT DOES NOT SHARE ITS USER OR GROUP ID WITH OTHER ACCOUNTS # AND THAT OWNS NO OTHER FILES OR PROCESSES ON THE SYSTEM. In # particular, don't specify nobody or daemon. PLEASE USE A DEDICATED # USER. # mail_owner = postfix # The default_privs parameter specifies the default rights used by # the local delivery agent for delivery to external file or command. # These rights are used in the absence of a recipient user context. # DO NOT SPECIFY A PRIVILEGED USER OR THE POSTFIX OWNER. # #default_privs = nobody # INTERNET HOST AND DOMAIN NAMES # # The myhostname parameter specifies the internet hostname of this # mail system. The default is to use the fully-qualified domain name # from gethostname(). $myhostname is used as a default value for many # other configuration parameters. # #myhostname = host.domain.tld #myhostname = virtual.domain.tld # The mydomain parameter specifies the local internet domain name. # The default is to use $myhostname minus the first component. # $mydomain is used as a default value for many other configuration # parameters. # #mydomain = domain.tld # SENDING MAIL # # The myorigin parameter specifies the domain that locally-posted # mail appears to come from. The default is to append $myhostname, # which is fine for small sites. If you run a domain with multiple # machines, you should (1) change this to $mydomain and (2) set up # a domain-wide alias database that aliases each user to # [email protected][email protected][email protected][email protected][email protected] Thank you!