Meu servidor não consegue enviar e-mail

Eu estava depurando o servidor de envio de e-mail do Discourse, mas encontrei um problema e espero obter ajuda de vocês!

DISCOURSE DOCTOR Ter Fev 3 12:57:50 PM CST 2026
OS: Linux instance-CvKJK0U4 6.12.38+deb13-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.12.38-1 (2025-07-16) x86_64 GNU/Linux

Found containers/app.yml

==================== YML SETTINGS ====================
DISCOURSE_HOSTNAME=metatest.smtc2web.org
SMTP_ADDRESS=smtp.resend.com

DEVELOPER_EMAILS=akarinliu@outlook.com


SMTP_PASSWORD=Mt$ygA$@yMhnF9#$
SMTP_PORT=465

SMTP_USER_NAME=noreply@akarinliu.com

==================== DOCKER INFO ====================
DOCKER VERSION: Docker version 29.2.1, build a5c7197

DOCKER PROCESSES (docker ps -a)

CONTAINER ID   IMAGE                                 COMMAND                  CREATED          STATUS          PORTS                                                                                NAMES
3e1f56e5922e   local_discourse/app                   “/sbin/boot”             43 seconds ago   Up 43 seconds   0.0.0.0:8080->80/tcp, \[::\]:8080->80/tcp, 0.0.0.0:8443->443/tcp, \[::\]:8443->443/tcp   app
467515024af6   1panel/openresty:1.27.1.2-5-1-focal   “/usr/local/openrest…”   3 hours ago      Up 3 hours                                                                                           1Panel-openresty-0VRP

3e1f56e5922e   local_discourse/app                   “/sbin/boot”             43 seconds ago   Up 43 seconds   0.0.0.0:8080->80/tcp, \[::\]:8080->80/tcp, 0.0.0.0:8443->443/tcp, \[::\]:8443->443/tcp   app

Discourse container app is running

==================== PLUGINS ====================
- git clone https://github.com/discourse/docker_manager.git

No non-official plugins detected.

See https://github.com/discourse/discourse/blob/main/lib/plugin/metadata.rb for the official list.

========================================
Discourse version at metatest.smtc2web.org: NOT FOUND
Discourse version at localhost: NOT FOUND

==================== MEMORY INFORMATION ====================
RAM (MB): 2069

Mem: 1973 1480 217 33 493 492
Swap: 2047 291 1756

==================== DISK SPACE CHECK ====================
---------- OS Disk Space ----------
df: /var/discourse: No such file or directory
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 30G 11G 18G 37% /

==================== DISK INFORMATION ====================
Disk /dev/sda: 30 GiB, 32212254720 bytes, 62914560 sectors
Disk model: QEMU HARDDISK
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x86a4d272

Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 62914526 62912479 30G 83 Linux

==================== END DISK INFORMATION ====================

==================== MAIL TEST ====================
For a robust test, get an address from http://www.mail-tester.com/
Or just send a test message to yourself.
Email address for mail test? (‘n’ to skip) [akarinliu@outlook.com]:
Sending mail to akarinliu@outlook.com. . .
Testing sending to akarinliu@outlook.com using smtp.resend.com:465, username:noreply@akarinliu.com with plain auth.
==================================== ERROR =====================================
UNKNOWN ERROR!
Net::ReadTimeout: Net::ReadTimeout with #TCPSocket:(closed)
=================================== SOLUTION ===================================
This is not a common error. No recommended solution exists!

Please report the exact error message above to https://meta.discourse.org/

(And a solution, if you find one!)

Replacing: SMTP_PASSWORD
Replacing: LETSENCRYPT_ACCOUNT_EMAIL
Replacing: DEVELOPER_EMAILS
Replacing: DISCOURSE_DB_PASSWORD
Replacing: Sending mail to

==================== DONE! ====================
Would you like to serve a publicly available version of this file? (Y/n) n
Publicly available log not generated.

You can examine the output of this script with
LESS=-Ri less /tmp/discourse-debug.txt

BUT FIRST, make sure that you know the first three commands below!!!

Commands to know when viewing the file with the above command (called ‘less’):
q – quit
/error – search for the word ‘error’
n – search for the next occurrence
g – go to the beginning of the file
f – go forward a page
b – go back a page
G – go to the end of the file
```

Você expôs suas credenciais SMTP e e-mail pessoal, provavelmente deveria removê-las antes que um indexador as encontre.

Alguma coisa nos logs? Qual provedor de nuvem você está usando? Alguns provedores como o Linode bloqueiam portas SMTP. Eu suspeitaria de um bloqueio com base no tempo limite, mas você também pode testar da sua LAN, desde que seu provedor de serviços de internet não esteja fazendo nada estranho.