I simply define my virtual domains in Postfix:

VIRTUAL DOMAINS

virtual_alias_domains = new.domain virtual_alias_maps = hash:/etc/postfix/virtual Then, in /etc/postfix/virtual, I add the alias: newuser@new.domain newuser And that’s it. Could you share your doveconf -n?

That set up is different than what I am trying to achieve. You have a virtual alias set up, which redirects mail from an email address to an arbitrary linux user. I am trying to avoid creating linux users for every email account, which is why I need to be able to use dovecot's multiple authentication database feature to facilitate virtual mailboxes. Here is that section from my /etc/postfix/main.cf:

virtual_mailbox_domains = example.net
virtual_uid_maps = static:1001
virtual_gid_maps = static:1001
virtual_mailbox_base = /var/postfix/virtual
virtual_mailbox_maps = hash:/etc/postfix/virtual/recipients
virtual_alias_maps = hash:/etc/postfix/virtual/aliases
virtual_alias_domains = hash:/etc/postfix/virtual/domains

Then the mailbox is defined in /etc/postfix/virtual/recipients:

user@example.net    example.net/user

Which means that rather than being set up as a linux user with a /home directory, user@example.net should have a virtual mailbox in /var/postfix/virtual/example.net/user. This actually works as far as postfix is concerned, and as the root user I can peek in that folder to see a message sent to it from my personal email account. Then here is doveconf -n:

# 2.4.1-4 (7d8c0e5759): /etc/dovecot/dovecot.conf
# Pigeonhole version 2.4.1-4 (0a86619f)
# OS: Linux 6.12.57+deb13-amd64 x86_64 Debian 13.2 
# Hostname: example.com
dovecot_config_version = 2.4.1
auth_mechanisms = plain login
auth_username_format = %{user}
dovecot_storage_version = 2.4.1
mail_driver = sdbox
mail_inbox_path = ~/Mail/Inbox
mail_path = ~/Mail
protocols = imap
ssl = required
ssl_server {
  cert_file = /etc/letsencrypt/live/mail.example.com/fullchain.pem
  dh_file = /usr/share/dovecot/dh.pem
  key_file = /etc/letsencrypt/live/mail.example.com/privkey.pem
  prefer_ciphers = server
}
userdb passwd-file {
  passwd_file_path = /etc/dovecot/passwd/%{user | domain}
}
userdb passwd {
}
passdb passwd-file {
  passwd_file_path = /etc/dovecot/passwd/%{user | domain}
}
passdb pam {
}
namespace inbox {
  inbox = yes
  mailbox Drafts {
    auto = subscribe
    special_use = "\\Drafts"
  }
  mailbox Junk {
    auto = subscribe
    autoexpunge = 30d
    special_use = "\\Junk"
  }
  mailbox Sent {
    auto = subscribe
    special_use = "\\Sent"
  }
  mailbox Trash {
    special_use = "\\Trash"
  }
  mailbox Archive {
    special_use = "\\Archive"
  }
}
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0660
    user = postfix
  }
}
protocol lda {
  mail_plugins = sieve
}
protocol lmtp {
  mail_plugins = sieve
}
protocol pop3 {
  pop3_no_flag_updates = yes
  pop3_uidl_format = UID%{uid}-%{uidvalidity}
}
sieve_script default {
}

Basically the problem is that this virtual mailbox user has a mailbox that receives mail, but the user cannot log onto their account with an email client. My guess is that I either have misconfigured the userdb and/or passdb entries in the dovecot.conf file, or the passwd-file at /etc/dovecot/passwd/example.net I created is not formatted correctly, because the ultimate problem is that the system cannot authenticate the user when they attempt to connect via imap/smtp. From all of the documentation and help threads referenced in my first message, I cannot tell what I've done wrong and I'm at a total loss.

Thanks for the prompt reply. This is my first time using one of these mail lists, so I did not see you responded right away.