systemctl is-active maddy
systemctl status maddy --no-pager | sed -n '1,10p'
ss -ltn | grep -E ':(25|465|587|143|993)\b'

active
● maddy.service - maddy mail server
     Loaded: loaded (/etc/systemd/system/maddy.service; enabled; vendor preset: enabled)
     Active: active (running) since Mon 2026-10-19 09:20:31 UTC; 3h 16min ago
       Docs: man:maddy(1)
             man:maddy.conf(5)
             https://maddy.email
   Main PID: 11773 (maddy)
     Status: "Configuration running."
      Tasks: 11 (limit: 5753)
     Memory: 15.6M
LISTEN 0      4096       127.0.0.1:25        0.0.0.0:*
LISTEN 0      4096               *:587             *:*
LISTEN 0      4096               *:993             *:*
LISTEN 0      4096               *:143             *:*
LISTEN 0      4096               *:465             *:*

ps -o pid,user,rss,etime,cmd -C maddy

  PID USER       RSS     ELAPSED CMD
12027 maddy    27892       05:56 /usr/local/bin/maddy --config /etc/maddy/relay.conf run
12298 maddy    31640       00:09 /usr/local/bin/maddy run

maddy version
maddy verify-config

0.9.6 linux/amd64 go1.27.1

default config: /etc/maddy/maddy.conf
default state_dir: /var/lib/maddy
default runtime_dir: /run/maddy
table.file: ignoring non-existent file: /etc/maddy/aliases
No errors detected

maddy creds list
maddy imap-acct list
maddy imap-mboxes list admin@lab.example.org
maddy imap-msgs list admin@lab.example.org INBOX

admin@lab.example.org
demo@lab.example.org
admin@lab.example.org
demo@lab.example.org
INBOX   [\HasNoChildren]
Sent    [\Sent \HasNoChildren]
Trash   [\Trash \HasNoChildren]
Junk    [\Junk \HasNoChildren]
Drafts  [\Drafts \HasNoChildren]
Archive [\Archive \HasNoChildren]
UID 1:  <news@client.mailtest.internal> - Clean inbox delivery
  [\Recent], 2026-10-19 07:39:03 +0000 UTC

UID 2:  <MAILER-DAEMON@lab.example.org> - Undelivered Mail Returned to Sender
  [\Recent], 2026-10-19 07:39:21 +0000 UTC
...

du -sh /var/lib/maddy
ls -la /var/lib/maddy

272K    /var/lib/maddy
total 180
drwxr-xr-x 7 maddy maddy  4096 Oct 19 09:20 .
drwxr-xr-x 1 root  root   4096 Oct 19 07:55 ..
drwx------ 2 maddy maddy  4096 Oct 19 07:29 buffer
-rw-r--r-- 1 maddy maddy 12288 Oct 19 07:30 credentials.db
drwxr-xr-x 2 maddy maddy  4096 Oct 19 07:29 dkim_keys
-rw-r----- 1 maddy maddy 86016 Oct 19 09:20 imapsql.db
-rw-r----- 1 maddy maddy 32768 Oct 19 09:20 imapsql.db-shm
-rw-r----- 1 maddy maddy  4152 Oct 19 09:20 imapsql.db-wal
drwxr-xr-x 2 maddy maddy  4096 Oct 19 09:20 messages
drwxr-xr-x 2 maddy maddy  4096 Oct 19 07:29 mtasts_cache
drwxr-xr-x 2 maddy maddy  4096 Oct 19 09:20 remote_queue

{"MsgMeta":{"ID":"591a074f","OriginalFrom":"admin@lab.example.org","DontTraceSender":true,"Quarantine":false,"OriginalRcpts":{},"SMTPOpts":{"Body":"","Size":0,"RequireTLS":false,"UTF8":false,"Return":"","EnvelopeID":"","Auth":null},"Conn":null,"TLSRequireOverride":false},"From":"admin@lab.example.org","To":["relayuser@mailtest.internal"],"FailedRcpts":null,"TemporaryFailedRcpts":null,"RcptErrs":{},"TriesCount":null,"FirstAttempt":"2026-10-19T12:38:36.938212519Z","LastAttempt":"2026-10-19T12:40:50.903972862Z"}

cannot use MX        {"domain":"mailtest.internal","msg_id":"591a074f-6ad60f4c","reason":"dialer: dial tcp 127.0.0.2:25: connect: connection timed out","remote_server":"relayhost.mailtest.internal."}
delivery attempt failed        {"domain":"mailtest.internal","msg_id":"591a074f","rcpt":"relayuser@mailtest.internal","reason":"dialer: dial tcp 127.0.0.2:25: connect: connection timed out","remote_server":"relayhost.mailtest.internal.","smtp_code":451,"smtp_enchcode":"5.4.0","smtp_msg":"No usable MXs, last err: dialer: dial tcp 127.0.0.2:25: connect: connection timed out","target":"remote"}
will retry        {"attempts_count":{"relayuser@mailtest.internal":1},"msg_id":"591a074f","next_try_delay":"14m59.999998332s","rcpts":["relayuser@mailtest.internal"]}

cannot use MX        {"domain":"mailtest.internal","msg_id":"cac1b963-6ad60f1a","reason":"dialer: dial tcp 127.0.0.3:25: connect: connection refused","remote_server":"relayhost.mailtest.internal."}
delivery attempt failed        {"domain":"mailtest.internal","msg_id":"cac1b963","rcpt":"relayuser@mailtest.internal","reason":"dialer: dial tcp 127.0.0.3:25: connect: connection refused","remote_server":"relayhost.mailtest.internal.","smtp_code":550,"smtp_enchcode":"5.4.0","smtp_msg":"No usable MXs, last err: dialer: dial tcp 127.0.0.3:25: connect: connection refused","target":"remote"}
not delivered, permanent error        {"msg_id":"cac1b963","rcpt":"relayuser@mailtest.internal"}
generated failed DSN        {"dsn_id":"eee7af5a","msg_id":"cac1b963"}

TLS verify error, trying without authentication        {"domain":"mailtest.internal","msg_id":"591a074f-6ad61356","reason":"tls: failed to verify certificate: x509: certificate relies on legacy Common Name field, use SANs instead","remote_server":"relayhost.mailtest.internal."}
delivery attempt failed        {"msg_id":"591a074f","rcpt":"relayuser@mailtest.internal","reason":"SMTP error 554: Internal server error (msg ID = 445bdec1)","remote_server":"relayhost.mailtest.internal.","smtp_code":554,"smtp_enchcode":"5.0.0","smtp_msg":"relayhost.mailtest.internal. said: Internal server error (msg ID = 445bdec1)"}
not delivered, permanent error        {"msg_id":"591a074f","rcpt":"relayuser@mailtest.internal"}
generated failed DSN        {"dsn_id":"c327fa46","msg_id":"591a074f"}

Subject: Undelivered Mail Returned to Sender
From: MAILER-DAEMON@lab.example.org
To: admin@lab.example.org
Auto-Submitted: auto-replied

This is the mail delivery system at mail.lab.example.org.
...
Contact the postmaster for further assistance, provide the Message ID (below):

Message ID: 591a074f
Arrival: 2026-10-19 12:38:36 +0000 UTC
Last delivery attempt: 2026-10-19 12:40:50 +0000 UTC

Delivery to relayuser@mailtest.internal failed with error: SMTP error 554: relayhost.mailtest.internal. said: Internal server error (msg ID = 445bdec1)

Last-Attempt-Date: Mon, 19 Oct 2026 12:40:50 +0000
Arrival-Date: Mon, 19 Oct 2026 12:38:36 +0000
X-Maddy-Msgid: 591a074f

systemctl stop maddy
ls /var/lib/maddy/remote_queue/
rm /var/lib/maddy/remote_queue/<msg_id>.{header,body,meta}   # 清指定消息
# 或 rm /var/lib/maddy/remote_queue/*                          # 清空全部
systemctl start maddy

journalctl -u maddy --no-pager                      # 全量
journalctl -u maddy -n 50 --no-pager                # 最近 50 行
journalctl -u maddy --since "-15 min" --no-pager    # 最近 15 分钟
journalctl -u maddy -f                              # 跟踪

journalctl -u maddy --no-pager --since "30 minutes ago" | grep "cac1b963"

submission: incoming message        {"msg_id":"cac1b963","sender":"admin@lab.example.org","src_host":"mail.lab.example.org","src_ip":"127.0.0.1:38852","username":"admin@lab.example.org"}
submission: RCPT ok        {"msg_id":"cac1b963","rcpt":"relayuser@mailtest.internal"}
submission: accepted        {"msg_id":"cac1b963"}
cannot use MX        {"domain":"mailtest.internal","msg_id":"cac1b963-6ad60f1a","reason":"dialer: dial tcp 127.0.0.3:25: connect: connection refused","remote_server":"relayhost.mailtest.internal."}
delivery attempt failed        {"domain":"mailtest.internal","msg_id":"cac1b963",...,"smtp_code":550,...}
not delivered, permanent error        {"msg_id":"cac1b963","rcpt":"relayuser@mailtest.internal"}

openssl x509 -in /etc/maddy/certs/mail.lab.example.org/fullchain.pem -noout -subject -dates

subject=CN = mail.lab.example.org
notBefore=Oct 19 07:29:14 2026 GMT
notAfter=Oct 19 07:29:14 2027 GMT

systemctl reload maddy

reloading server...
submission: listening on tls://0.0.0.0:465
imap: listening on tls://0.0.0.0:993
systemd[1]: Reloaded maddy mail server.

echo | openssl s_client -connect 127.0.0.1:993 2>/dev/null | grep -E 'subject=|Protocol|Verify return code'
echo | openssl s_client -starttls smtp -connect 127.0.0.1:587 2>/dev/null | grep -E 'subject=|Verify return code'

subject=CN = mail.lab.example.org
New, TLSv1.3, Cipher is TLS_AES_128_GCM_SHA256
Verify return code: 18 (self-signed certificate)
subject=CN = mail.lab.example.org
Verify return code: 18 (self-signed certificate)

ln -s /etc/letsencrypt/live/mail.lab.example.org /etc/maddy/certs/mail.lab.example.org
setfacl -R -m u:maddy:rX /etc/letsencrypt/live /etc/letsencrypt/archive
certbot renew --deploy-hook "systemctl reload maddy"

COMMANDS:
   verify-config  Check configuration file for errors
   run            Start the server
   version        Print version and build metadata, then exit
   hash           Generate password hashes for use with pass_table
   imap-mboxes    IMAP mailboxes (folders) management
   imap-msgs      IMAP messages management
   imap-acct      IMAP storage accounts management
   creds          Local credentials management

printf '%s' 'q1w2e3r4' | maddy creds password demo@lab.example.org

table.file: ignoring non-existent file: /etc/maddy/aliases
Failed to disable terminal output: TurnOnRawIO: failed to get flags: inappropriate ioctl for device
Enter new password: exit=0

maddy creds remove --yes <用户名>
maddy imap-acct remove --yes <用户名>

maddy imap-acct appendlimit admin@lab.example.org
maddy imap-acct appendlimit admin@lab.example.org 52428800   # 设置 50MB（字节）

mkdir -p /tmp/maddy-bak
python3 - <<'PYEOF'
import sqlite3, os
for db in ["imapsql.db", "credentials.db"]:
    src = sqlite3.connect(f"/var/lib/maddy/{db}")
    dst = sqlite3.connect(f"/tmp/maddy-bak/{db}")
    src.backup(dst); dst.close(); src.close()
    chk = sqlite3.connect(f"/tmp/maddy-bak/{db}").execute("PRAGMA integrity_check").fetchone()[0]
    print(db, "backup+integrity:", chk)
PYEOF

imapsql.db backup+integrity: ok
credentials.db backup+integrity: ok

tar -C /var/lib/maddy -czf /tmp/maddy-bak/files.tgz messages dkim_keys mtasts_cache
tar -C /etc -czf /tmp/maddy-bak/etc.tgz maddy

systemctl stop maddy
tar -C /var/lib -czf /tmp/maddy-bak/cold-full.tgz maddy
systemctl start maddy

cold backup: 20K 28 entries

systemctl stop maddy
mv /var/lib/maddy /var/lib/maddy.pre-restore
tar -C /var/lib -xzf /tmp/maddy-bak/cold-full.tgz
chown -R maddy:maddy /var/lib/maddy
systemctl start maddy

active
== creds list ==
admin@lab.example.org
demo@lab.example.org
== admin INBOX 消息数 ==
9
== 队列文件数 ==
3

openmetrics tcp://127.0.0.1:9749 { }

maddy verify-config && systemctl restart maddy
journalctl -u maddy -n 5 --no-pager | grep openmetrics

openmetrics: listening on tcp://127.0.0.1:9749

curl -s http://127.0.0.1:9749/metrics

# HELP go_goroutines Number of goroutines that currently exist.
# TYPE go_goroutines gauge
go_goroutines 26
# HELP go_info Information about the Go environment.
# TYPE go_info gauge
go_info{version="go1.27.1"} 1

curl -s http://127.0.0.1:9749/metrics | grep -iE 'queue|smtp|delivery|imap|dkim|msg'

scrape_configs:
  - job_name: maddy
    static_configs:
      - targets: ['mail.example.com:9749']

smtp: DATA error        {"msg_id":"445bdec1","reason":"external: open messages/0142468c36c9a8ec6a736c2f1725b7ce: no such file or directory"}