Please check your mail log for errors.

# Pigeonhole version 0.5.4 ()
# OS: Linux 4.19.0-16-amd64 x86_64 Debian 10.9 ext4
# Hostname: mail.xxxxx.com
auth_debug = yes
auth_debug_passwords = yes
auth_mechanisms = plain login
auth_verbose = yes
auth_verbose_passwords = yes
debug_log_path = /var/log/dovecot-debug
log_path = /var/log/dovecot
mail_debug = yes
mail_location = maildir:/var/mail/%d/%n:INDEX=/var/mail/%d/%n/indexes
mail_privileged_group = mail
namespace inbox {
inbox = yes
location =
mailbox Drafts {
special_use = \Drafts
}
mailbox Enviados {
special_use = \Sent
}
mailbox Junk {
special_use = \Junk
}
mailbox Sent {
special_use = \Sent
}
mailbox «Sent Messages» {
special_use = \Sent
}
mailbox Trash {
special_use = \Trash
}
prefix =
separator = .
}
passdb {
args = /etc/dovecot/dovecot-mysql.conf.ext
driver = sql
}
plugin {
sieve = file:~/sieve;active=~/.dovecot.sieve
}
protocols = » imap lmtp pop3 lmtp»
service auth-worker {
user = vmail
}
service auth {
unix_listener /var/spool/postfix/private/auth {
group = postfix
mode = 0666
user = postfix
}
unix_listener auth-userdb {
mode = 0600
user = vmail
}
user = dovecot
}
service lmtp {
unix_listener /var/spool/postfix/private/dovecot-lmtp {
group = postfix
mode = 0600
user = postfix
}
}
service stats {
unix_listener stats-reader {
group = vmail
mode = 0660
user = vmail
}
unix_listener stats-writer {
group = vmail
mode = 0660
user = vmail
}
}
ssl_cert = </etc/letsencrypt/live/mail.xxxxx.com/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-mysql.conf.ext
driver = sql
}
protocol lmtp {
mail_plugins = " sieve"
}
protocol lda {
mail_plugins = " quota sieve"
postmaster_address = admin@xxxx.com
}
protocol imap {
mail_max_userip_connections = 10
}
I can't find the error

Please try to follow the steps again, and check if something is missing in the configuration files.

For Kazishe et al, there is a mistake in the given config for /etc/dovecot/dovecot-sql.conf.ext where password_query and user_query are using two different directory formats.

password_query is using /var/vmail/%d/%n as the maildir, but user_query is using /var/vmail/%d/%u

%n expands to “user”, where %u expands to “user@domian.tld”. This is probably why there are issues with Dovecot saving under a different directory than it is later looking for the messages in. You need to make them both the same with %n. Better yet, use /var/vmail/%Ld/%Ln so that the domain and username are lower-cased. This way if a message gets through with a uSeR@domain.tld it doesn’t get stored in a different directory from user@domain.tld.

Here is the full file:

# /etc/dovecot/dovecot-sql.conf.ext
driver = mysql
connect = host=/var/run/mysqld/mysqld.sock dbname=postfix user=postfix password=PICKAPASSWORD
default_pass_scheme = MD5-CRYPT
password_query = SELECT username as user, password, ‘/var/vmail/%Ld/%Ln’ as userdb_home, ‘maildir:/var/vmail/%Ld/%Ln’ as userdb_mail, 150 as userdb_uid, 8 as userdb_gid FROM mailbox WHERE username = ‘%u’ AND active = ‘1’
user_query = SELECT ‘/var/vmail/%Ld/%Ln’ as home, ‘maildir:/var/vmail/%Ld/%Ln’ as mail, 150 AS uid, 8 AS gid, concat(‘dirsize:storage=’, quota) AS quota FROM mailbox WHERE username = ‘%u’ AND active = ‘1’
iterate_query = SELECT username AS user FROM mailbox WHERE active = ‘1’ ORDER BY username

Check the mail location set on /etc/dovecot/conf.d/10-mail.conf.

May 6 20:29:59 serverhostname dovecot: pop3(user@mydomain.com): Debug: Effective uid=150, gid=8, home=/var/vmail/mydomain.com/user@mydomain.com
May 6 20:29:59 serverhostname dovecot: pop3(user@mydomain.com): Debug: Namespace inbox: type=private, prefix=, sep=, inbox=yes, hidden=no, list=yes, subscriptions=yes location=maildir:/var/vmail/mydomain.com/user@mydomain.com
May 6 20:29:59 serverhostname dovecot: pop3(user@mydomain.com): Debug: maildir++: root=/var/vmail/mydomain.com/user@mydomain.com, index=, indexpvt=, control=, inbox=/var/vmail/mydomain.com/user@mydomain.com, alt=

Please helps