Ubuntu, postfix, mail dont work

[mscadela]

Hello,
mail don't work:
###############
[2024-01-03 11:36:41] DEBUG Sending mail using SMTP/6.7.2[client:6.7.2]
[2024-01-03 11:36:41] DEBUG [agkXBePEfPg] Resolved localhost as 127.0.0.1 [cache miss]
[2024-01-03 11:36:41] ERROR [agkXBePEfPg] connect ECONNREFUSED 127.0.0.1:25
[2024-01-03 11:36:41] DEBUG [agkXBePEfPg] Closing connection to the server using "destroy"
[2024-01-03 11:36:41] ERROR Send Error: connect ECONNREFUSED 127.0.0.1:25
{"name":"web","hostname":"4b463be235a9","pid":175,"level":40,"err":{"message":"error sending message","name":"OError","stack":"OError: error sending message\n at Object.sendEmail (/overleaf/services/web/app/src/Features/Email/EmailSender.js:99:11)\n at process.processTicksAndRejections (node:internal/process/task_queues:95:5)\n at async Object.sendEmail (/overleaf/services/web/app/src/Features/Email/EmailHandler.js:25:3)\ncaused by:\n Error: connect ECONNREFUSED 127.0.0.1:25\n at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1555:16)","info":{}},"msg":"failed to send activation email","time":"2024-01-03T11:36:41.450Z","v":0}
################
SHARELATEX_EMAIL_FROM_ADDRESS=team@example.com
SHARELATEX_EMAIL_SMTP_HOST=localhost
SHARELATEX_EMAIL_SMTP_PORT=25
SHARELATEX_EMAIL_SMTP_SECURE=true
SHARELATEX_EMAIL_SMTP_USER=overleaf
SHARELATEX_EMAIL_SMTP_PASS=password
SHARELATEX_EMAIL_SMTP_LOGGER=true
SHARELATEX_EMAIL_SMTP_TLS_REJECT_UNAUTH=false
SHARELATEX_EMAIL_SMTP_IGNORE_TLS=false
#################
sending email from the server works, but in overleaf I receive a "ERROR Send Error: connect ECONNREFUSED 127.0.0.1:25"
Can anyone help?
Thank you so much and a Happy New Year!

[Darkdragon84]

Have you tried sending a test email from inside the sharelatex docker container, e.g. using telnet?

docker exec -it sharelatex bash
// now we are root inside the docker container
apt-get update
apt-get install telnet
telnet 127.0.0.1 25
// send email following steps from https://prox.dev/sending-emails-with-telnet/

My guess is that your smtp server is not reachable from inside the docker container. Have you made sure it is accessible from inside the container?