SMTP does not work...

[marcogaio]

I'm testing Claper (wondeful!) for a Linux User group here in north east of Italy (Pordenone Linux User Group, PNLug).

I was able to run the docker container, fix some issue putting it behind a nginx reverse proxy (if needed, i can provide feedback on that, because i've not found info on documents) but still Claper does not send email.

Docker VM is part of a little virtualization setup, where there's also an SMTP server/relay that send email for all the services. I've setup .env as:

SMTP_RELAY=10.21.13.180
SMTP_AUTH=never
SMTP_PORT=25
SMTP_TLS=never
SMTP_SSL=false

But email does not get sent; even, i've sniffed on network interfaces, end there's even NO SMTP traffic, so Claper seems never tries to send email...

Network and SMTP server reachability seems fine:

root@vdockerpnlug1:~# docker ps
CONTAINER ID   IMAGE                            COMMAND                  CREATED        STATUS                  PORTS                                       NAMES
ff6a3668b491   ghcr.io/claperco/claper:latest   "sh -c '/app/bin/cla…"   20 hours ago   Up 20 hours (healthy)   0.0.0.0:4000->4000/tcp, :::4000->4000/tcp   claper-app-1
dddc4a72e4f4   postgres:15                      "docker-entrypoint.s…"   20 hours ago   Up 20 hours (healthy)   0.0.0.0:5432->5432/tcp, :::5432->5432/tcp   claper-db-1
root@vdockerpnlug1:~# docker exec -it  ff6a3668b491 bash
ff6a3668b491:/app# nc 10.21.13.180 25
220 mail.artemis.pnlug.it ESMTP Exim 4.94.2 Mon, 14 Oct 2024 14:17:05 +0200
help
214-Commands supported:
214 AUTH STARTTLS HELO EHLO MAIL RCPT DATA BDAT NOOP QUIT RSET HELP
quit
221 mail.artemis.pnlug.it closing connection

What i'm doing wrong?! Thanks.

[alxlion]

Ciao Marco!

Claper doesn't send a lot of emails, it only sends an email when

• You request a password change
• Add a facilitator when you edit/create an event

Have you tried this to test your smtp configuration?

[marcogaio]

Sorry, forgot a piece; my complete email configuration in `.env ' is:

MAIL_TRANSPORT=smtp
MAIL_FROM=tech@pnlug.it
MAIL_FROM_NAME=Claper

SMTP_RELAY=10.21.13.180
SMTP_AUTH=never
SMTP_PORT=25
SMTP_TLS=never
SMTP_SSL=false

I've tried to:

1. change my password
2. change my email
3. reset my password

no email get sent...

[marcogaio]

Claper doesn't send a lot of emails, it only sends an email when

Sorry, forgot to say.

So there's no confirmation mechanism for user creation? This cannot lead to user creation bombing attacks?

[alxlion]

Email is always a pain to manage, so we try to avoid it at all costs. We use anti-bot and anti-spam on the frontend of our instance to avoid any bombing.

Regarding your issue, are you sure that the container has access to 10.21.13.180?

[marcogaio]

Email is always a pain to manage, so we try to avoid it at all costs. We use anti-bot and anti-spam on the frontend of our instance to avoid any bombing.

Ok... have some example configuration/hint/... to share? Thanks.

Regarding your issue, are you sure that the container has access to 10.21.13.180?

Sure! As you can see in my first post, i spawned a shell into the claper container and accessed the mail server.

[alxlion]

We just added EMAIL_CONFIRMATION to enable email confirmation at registration if you need so (https://docs.claper.co/self-hosting/configuration.html#email-confirmation) (available on the dev version).

Do you have any app logs in Claper to share?

[marcogaio]

We just added EMAIL_CONFIRMATION to enable email confirmation at registration if you need so (https://docs.claper.co/self-hosting/configuration.html#email-confirmation) (available on the dev version).

I've stopped, updated and restarted the container, setting that variable in .env; nothing changed...

Do you have any app logs in Claper to share?

Do you mean the log i can obtain with `docker logs --follow e9e6c0a6cc8b '? Seems me contain nothing more then HTTP GET and WebSocket request.

Particulary, there's no SMTP/email row...

[alxlion]

Sorry for the late reply, I am trying to reproduce this and investigate

[bethgocs]

same issue... no smtp lines in logfile... also did the nc test... mailserver is reachable

[alxlion]

In the dev branch, a new mail job handling system has been implemented, which will show error logs in the console if something doesn't work properly:

[info] {"error":"** (Oban.PerformError) Claper.Workers.Mailers failed with {:error, {:retries_exceeded, {:network_failure, ~c\"localhost\", {:error, {:options, :incompatible, [verify: :verify_peer, cacerts: :undefined]}}}}}","args":{"email":"test@test.com","event_name":"hello","type":"event_invitation","url":"http://localhost:4000/events"},"id":13,"meta":{},"state":"failure","max_attempts":20,"queue":"mailers","worker":"Claper.Workers.Mailers","source":"oban","event":"job:exception","duration":97637,"queue_time":1036380,"attempt":6,"tags":[]}

You can test and come back here with the message log.

[bethgocs]

Hope this will help. Tried it on Port 25 and 465. Also successfully send a mail with netcat (https://learn.microsoft.com/de-de/exchange/use-telnet-to-test-smtp-communication-exchange-2013-help). Mailserver works and reachable.

app-1 | 09:02:53.279 [info] {"args":{"type":"reset","url":"http:///users/reset_password/","user_id":1},"id":1,"meta":{},"system_time":1734858173278930823,"max_attempts":20,"queue":"mailers","worker":"Claper.Workers.Mailers","source":"oban","event":"job:start","attempt":3,"tags":[]}
app-1 | 09:02:53.294 [info] {"error":"** (Oban.PerformError) Claper.Workers.Mailers failed with {:error, {:retries_exceeded, {:network_failure, ~c"mail.", {:error, {:options, :incompatible, [verify: :verify_peer, cacerts: :undefined]}}}}}","args":{"type":"reset","url":"http:///users/reset_password/***","user_id":1},"id":1,"meta":{},"state":"failure","max_attempts":20,"queue":"mailers","worker":"Claper.Workers.Mailers","source":"oban","duration":12833,"event":"job:exception","queue_time":57686,"attempt":3,"tags":[]}

[alxlion]

Hope this will help. Tried it on Port 25 and 465. Also successfully send a mail with netcat (https://learn.microsoft.com/de-de/exchange/use-telnet-to-test-smtp-communication-exchange-2013-help). Mailserver works and reachable.

app-1 | 09:02:53.279 [info] {"args":{"type":"reset","url":"http:///users/reset_password/","user_id":1},"id":1,"meta":{},"system_time":1734858173278930823,"max_attempts":20,"queue":"mailers","worker":"Claper.Workers.Mailers","source":"oban","event":"job:start","attempt":3,"tags":[]}

app-1 | 09:02:53.294 [info] {"error":"** (Oban.PerformError) Claper.Workers.Mailers failed with {:error, {:retries_exceeded, {:network_failure, ~c"mail.", {:error, {:options, :incompatible, [verify: :verify_peer, cacerts: :undefined]}}}}}","args":{"type":"reset","url":"http:///users/reset_password/***","user_id":1},"id":1,"meta":{},"state":"failure","max_attempts":20,"queue":"mailers","worker":"Claper.Workers.Mailers","source":"oban","duration":12833,"event":"job:exception","queue_time":57686,"attempt":3,"tags":[]}

Thanks I will investigate further, can you provide me your docker compose and details about your smtp server like TLS/SSL, service used (postfix or any other) to help me reproduce it on my side ? Thanks

[bethgocs]

Thanks I will investigate further, can you provide me your docker compose and details about your smtp server like TLS/SSL, service used (postfix or any other) to help me reproduce it on my side ? Thanks

Hi here is the requested Information... I use Mailcow (Postfix) as MTA

docker-compose.yaml
[...]
app:
#image: ghcr.io/claperco/claper:latest # or build: .
image: ghcr.io/claperco/claper:dev # or build: .
ports:
- 127.0.0.1:4000:4000
restart: unless-stopped
volumes:
- "./claper-uploads:/app/uploads"
healthcheck:
test: curl --fail http://localhost:4000 || exit 1
retries: 3
start_period: 20s
timeout: 5s
env_file: .env
depends_on:
db:
condition: service_healthy
labels:
- "traefik.enable=true"
- "traefik.docker.network=traefik"
- "traefik.http.routers.poll.rule=Host(*.****.**)"
- "traefik.http.routers.poll.entrypoints=websecure"
- "traefik.http.routers.poll.tls.certresolver=le"
- 'traefik.http.services.poll.loadbalancer.server.port=4000'
- com.centurylinklabs.watchtower.enable=true
networks:
- traefik
[...]

.env

Mail configuration

MAIL_TRANSPORT=smtp
MAIL_FROM=noreply@.**
#MAIL_FROM=noreply@.**
MAIL_FROM_NAME=Claper

SMTP_RELAY=mail..**
#SMTP_RELAY=10.0.1.1
SMTP_USERNAME=noreply@.**
SMTP_PASSWORD=**
#SMTP_AUTH=always
SMTP_AUTH=if_available
#SMTP_PORT=465
SMTP_PORT=25
#SMTP_TLS=never
#SMTP_TLS=always
SMTP_TLS=if_available

ENABLE_ACCOUNT_CREATION=false
EMAIL_CONFIRMATION=false

Tried any of These Option in a lot of combinations

root@:/opt/claper# docker compose exec app sh
/app # nc .. 25
220 ..*** ESMTP Postcow

[alxlion]

Thanks, I have reproduced it successfully, I'm working on a fix