Helo

Local network with no internet name.
Mail are sent outside local network using my_isp.com as relay
Mail are centralized on the mail server

Say mail domain is : my_domain.net

Presently on the local network linux user can send mail to each other
Mail are stored on the corresponding linux user folder describe in postfix config
Code:
home_mailbox =
mail_spool_directory = /var/spool/mail/Maildir/
linux user can send mail outside
Code:
relayhost = [smtp.my_isp.com]:submission
Virtual mailboxes are configured like this :
Code:
virtual_mailbox_base = /var/mail/virtual/
virtual_mailbox_domains = hash:/etc/postfix/virtual_domain
virtual_mailbox_maps = hash:/etc/postfix/vmailbox
virtual_minimum_uid = 1000
virtual_uid_maps = hash:/etc/postfix/virtual_uids
virtual_gid_maps = hash:/etc/postfix/virtual_gids
virtual_alias_maps = hash:/etc/postfix/virtual
The generic file contain :
Code:
linux_user1@my_domain.net             user1@my_isp.com
linux_user2@my_domain.net             user2@dom1.com
linux_user3@my_domain.net             user3@dom2.com
virtual_domain file contains :
Code:
my_isp.com
gmail.com
dom1.com
virtual_vmailbox file contains :
Code:
user1@my_isp.com        my_isp--com/user1/
user2@dom1.com          dom1--com/user2/
virtual_uids file contains :
Code:
user1@my_isp.com    1003
user2@dom1.com      1005
virtual_gids file contains :
Code:
user1@my_isp.com    303
user2@dom1.com      303
nota : 303 is vmail group
virtual file contains :
Code:
 is empty
THe fetchmail config file is in folder /root/.fetchmailrc
Code:
# Configuration created Tue May 29 21:49:54 2018 by fetchmailconf 1.57
set postmaster   "postmaster"
set bouncemail
set no spambounce
set softbounce
set properties    ""

#
# This my config
#

set no bouncemail                # avoid loss on 4xx errors
                                         # on the other hand, 5xx errors get
                                         # more dangerous...

defaults:
timeout     300
antispam   -1
batchlimit  100
fetchlimit   5

poll pop.my_isp.com proto pop3
     user user1 with pass "passuser1" is "linux_user1" here keep ssl
What parameters tell fetchmail to store isp user mail ( user does not exists on the system ) in corresponding virtual mailboxes as configured in postfix main.cf.

Presently fetchmail store mail from user1@my_isp.com in linux user account '/var/spool/mail/Maildir/linux_user1' and not in '/var/spool/mail/virtual/user1'

I have test only with linux_user1 and the corresponding user1@my_isp.com

Any help is welcome