That appears to have done the trick.

Thank you for your quick response. 

I probably should have found that setting. Sorry. 

On Sun, Sep 12, 2021 at 10:39 AM Aki Tuomi <aki.tuomi@open-xchange.com> wrote:
Try

mail_location = maildir:/var/mail/vmail/%Ld/%Ln

Aki

> On 12/09/2021 19:38 C. Petro <petro@cpetro.us> wrote:
>
>
> To be more clear about my problem.
>
> This server will be hosting multiple email domains, and I would prefer to have the filesystem structured like /var/mail/vmail/<domain>/<user> rather than /var/mail/vmail/<user>@<domain>.
>
>
> On Sat, Sep 11, 2021 at 3:06 PM C. Petro <petro@cpetro.us> wrote:
> > I'm trying to build a mail server for a friend using Postfix, Dovecot and Postfixadmin, using Mariadb as the backend for user information and authentication.
> >
> > I've got it *almost* working.
> > (dovecot -n at the bottom because I don't think the problem is in the SQL)
> >
> > I have things up to the point where mail comes in, and where you can get Thunderbird to connect to Dovecot, but delivery is looking at a different directory than IMAP:
> > root@mailserver:/var/mail/vmail# find ./
> > ./
> > ./petro@republicofmean.com
> > ./petro@republicofmean.com/dovecot.index.log (http://petro@republicofmean.com/dovecot.index.log)
> > ./petro@republicofmean.com/dovecot-uidvalidity.6136d995 (http://petro@republicofmean.com/dovecot-uidvalidity.6136d995)
> > ./petro@republicofmean.com/tmp (http://petro@republicofmean.com/tmp)
> > <...>
> > ./petro@republicofmean.com/new (http://petro@republicofmean.com/new)
> > ./petro@republicofmean.com/subscriptions (http://petro@republicofmean.com/subscriptions)
> > ./republicofmean.com (http://republicofmean.com)
> > ./republicofmean.com/petro (http://republicofmean.com/petro)
> > ./republicofmean.com/petro/tmp (http://republicofmean.com/petro/tmp)
> > ./republicofmean.com/petro/cur (http://republicofmean.com/petro/cur)
> > ./republicofmean.com/petro/new (http://republicofmean.com/petro/new)
> > ./republicofmean.com/petro/new/1630897562.Vfd00Ib40009M307139.mailserver (http://republicofmean.com/petro/new/1630897562.Vfd00Ib40009M307139.mailserver)
> > <....>
> > ./republicofmean.com/petro/new/1630899062.Vfd00Ib40011M264001.mailserver (http://republicofmean.com/petro/new/1630899062.Vfd00Ib40011M264001.mailserver)
> > ./republicofmean.com/cer (http://republicofmean.com/cer)
> > ./republicofmean.com/cer/tmp (http://republicofmean.com/cer/tmp)
> > ./republicofmean.com/cer/cur (http://republicofmean.com/cer/cur)
> > ./republicofmean.com/cer/new (http://republicofmean.com/cer/new)
> > ./republicofmean.com/cer/new/1630900562.Vfd00Ib40013M218855.mailserver (http://republicofmean.com/cer/new/1630900562.Vfd00Ib40013M218855.mailserver)
> > ./republicofmean.com/cer/new/1630899062.Vfd00Ib40010M259724.mailserver (http://republicofmean.com/cer/new/1630899062.Vfd00Ib40010M259724.mailserver)
> >
> > The SQL I think Dovecot is using:
> > root@mailserver:/etc/dovecot# grep -i select dovecot-sql.conf.ext | grep -v "^#"
> > password_query = SELECT username as user, domain, password FROM mailbox WHERE username = '%u'
> > user_query = select CONCAT("/var/mail/vmail/",maildir) as home, 500 as uid, 500 as gid from mailbox where username="%u"
> >
> >
> > Here's what Postfix is using:
> > mysql_virtual_alias_domain_catchall_maps.cf (http://mysql_virtual_alias_domain_catchall_maps.cf):
> > query = SELECT goto FROM alias,alias_domain WHERE alias_domain.alias_domain = '%d' and alias.address = CONCAT('@', alias_domain.target_domain) AND alias.active = 1 AND alias_domain.active='1'
> > mysql_virtual_alias_domain_mailbox_maps.cf (http://mysql_virtual_alias_domain_mailbox_maps.cf):
> > query = SELECT maildir FROM mailbox,alias_domain WHERE alias_domain.alias_domain = '%d' and mailbox.username = CONCAT('%u', '@', alias_domain.target_domain) AND mailbox.active = 1 AND alias_domain.active='1'
> > mysql_virtual_alias_domain_maps.cf (http://mysql_virtual_alias_domain_maps.cf):
> > query = SELECT goto FROM alias,alias_domain WHERE alias_domain.alias_domain = '%d' and alias.address = CONCAT('%u', '@', alias_domain.target_domain) AND alias.active = 1 AND alias_domain.active='1'
> > mysql_virtual_alias_maps.cf (http://mysql_virtual_alias_maps.cf):
> > query = SELECT goto FROM alias WHERE address='%s' AND active = '1'
> > mysql_virtual_domains_maps.cf (http://mysql_virtual_domains_maps.cf):
> > query = SELECT domain FROM domain WHERE domain='%s' AND active = '1'
> > mysql_virtual_mailbox_limit_maps.cf (http://mysql_virtual_mailbox_limit_maps.cf):
> > query = SELECT quota FROM mailbox WHERE username='%s' AND active = '1'
> > mysql_virtual_mailbox_maps.cf (http://mysql_virtual_mailbox_maps.cf):
> > query = SELECT maildir FROM mailbox WHERE username='%s' AND active = '1'
> >
> >
> >
> >
> >
> >
> > # dovecot -n
> > # 2.3.7.2 (3c910f64b): /etc/dovecot/dovecot.conf
> > # Pigeonhole version 0.5.7.2 ()
> > # OS: Linux 5.4.0-81-generic x86_64 Ubuntu 20.04.3 LTS ext4
> > # Hostname: <redacted>
> > auth_mechanisms = plain login
> > log_path = /var/log/dovecot.log
> > login_greeting = Not your mail server
> > mail_location = maildir:/var/mail/vmail/%u/
> > mail_max_userip_connections = 50
> > mail_privileged_group = vmail
> > namespace inbox {
> >  inbox = yes
> >  location =
> >  mailbox Drafts {
> >  special_use = \Drafts
> >  }
> >  mailbox Junk {
> >  special_use = \Junk
> >  }
> >  mailbox Sent {
> >  special_use = \Sent
> >  }
> >  mailbox "Sent Messages" {
> >  special_use = \Sent
> >  }
> >  mailbox Trash {
> >  special_use = \Trash
> >  }
> >  prefix =
> > }
> > passdb {
> >  args = /etc/dovecot/dovecot-sql.conf.ext
> >  driver = sql
> > }
> > protocols = " imap lmtp pop3 submission"
> > service auth-worker {
> >  user = vmail
> > }
> > service auth {
> >  unix_listener /var/spool/postfix/private/auth {
> >  group = postfix
> >  mode = 0600
> >  user = postfix
> >  }
> >  unix_listener auth-userdb {
> >  mode = 0600
> >  user = vmail
> >  }
> >  user = dovecot
> > }
> > service imap-login {
> >  inet_listener imap {
> >  port = 143
> >  }
> >  inet_listener imaps {
> >  port = 993
> >  ssl = yes
> >  }
> > }
> > service lmtp {
> >  unix_listener lmtp {
> >  group = postfix
> >  mode = 0600
> >  user = postfix
> >  }
> > }
> > service pop3-login {
> >  inet_listener pop3 {
> >  port = 110
> >  }
> >  inet_listener pop3s {
> >  port = 995
> >  ssl = yes
> >  }
> > }
> > ssl_cert = </etc/letsencrypt/live/<redacted>/fullchain.pem
> > ssl_client_ca_dir = /etc/ssl/certs
> > ssl_dh = # hidden, use -P to show it
> > ssl_key = # hidden, use -P to show it
> > userdb {
> >  args = /etc/dovecot/dovecot-sql.conf.ext
> >  driver = 
> >