SMTP Config Help needed

Hi everyone,

i wanted to configure SMTP to be able to send invitations mails.
I have running Vaultwarden in docker behind a NPM with valid SSL certificate to enter the loginpage.
We have a SMTP Relais running on a server within a domain. The domain ends with .local
When i try to send a Testmail i´m getting following error message

Error sending SMTP test email
SMTP error: Connection error: Connection error: error:0A000086:SSL routines:tls_post_process_server_certificate:certificate verify failed:../ssl/statem/statem_clnt.c:1889: (self-signed certificate)

This is my config within docker-compose file

  - SMTP_HOST=servername.domain.local
  - SMTP_FROM=support@domain.de
  - SMTP_PORT=25
  - SMTP_SECURITY=starttls 
  - SMTP_USERNAME=support@domain.de
  - SMTP_PASSWORD=password
  - SMTP_TIMEOUT=15
  - SMTP_AUTH_MECHANISM=Login  # Options: Plain, Login, or CramMd5 
  - SMTP_DEBUG=true

How can i solve this issue?

I would look at common port settings. 25 would be SMTP security off and 587 with starttls.

Thx.

After a lot of try and error i have figured it out.
Wen don´t use any auth methods.
Sometimes a step back to simple things helps a lot