Rails ActionMailer 6.1 / Ruby 3.1.2 / docker : certificate verify failed (self signed certificate)

Question

Could someone please help me to troubleshoot/configure sending email with ssl/tls please ?

Ruby : 3.1.2
Rails : 6.1.7
net-smtp: 0.3.3
docker image : 3.1-slim
My own organisation SMTP serveur that responds like this on port 25

250-servername.mydomain
250-PIPELINING
250-SIZE
250-ETRN
250-STARTTLS
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250-DSN
250-SMTPUTF8
250 CHUNKING

I confirm without starttls it's fine

config.action_mailer.smtp_settings = {
      address:              ENV.fetch('MAIL_SMTP_SERVER'),
      port:                 ENV.fetch('MAIL_SMTP_PORT', '25'),
      domain:               ENV.fetch('MAIL_DOMAIN'),
      openssl_verify_mode: OpenSSL::SSL::VERIFY_NONE
    }

But I do want to use starttls or tls so i configure like this

config.action_mailer.smtp_settings = {
      address: ENV.fetch('MAIL_SMTP_SERVER'),
      port:    ENV.fetch('MAIL_SMTP_PORT', '25'),
      domain:  ENV.fetch('MAIL_DOMAIN')
    }

I put my .pem certificates files in /etc/ssl/certs folder (certificates provided by my organisation and generated by our own PKI)
but I still have this error

    OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 peeraddr=xx.xx.xx.xx:25 state=error: certificate verify failed (self signed certificate)
    /myapp/lib/tasks/notif.rake:16:in `block (2 levels) in <top (required)>'
    /myapp/bin/rails:5:in `require'
    /myapp/bin/rails:5:in `<top (required)>'
    /myapp/bin/spring:10:in `require'
    /myapp/bin/spring:10:in `block in <top (required)>'
    /myapp/bin/spring:7:in `<top (required)>'

With this other combination

    ssl: true,
    enable_starttls_auto: false,
    openssl_verify_mode: OpenSSL::SSL::VERIFY_PEER,
    ca_file: "/etc/ssl/certs/ca-certificates.crt",

I have this error :

    /bundle/gems/net-protocol-0.1.3/lib/net/protocol.rb:46:in `connect_nonblock': SSL_connect returned=1 errno=0 peeraddr=10.19.1.33:25 state=error: wrong version number (OpenSSL::SSL::SSLError)

How can I check if i use correct version ?

Any idea please ?

Here it is how i test sending my mail.
in irb inside my container:

    irb(main):005:0> mailer = ActionMailer::Base.new
    => #<ActionMailer::Base:0x00000000062fe8>
    irb(main):006:0> mailer.smtp_settings
    => {:address=>"xxxx.xxxxx.com", :port=>"25", :domain=>"xxxxxx", :ssl=>true, :enable_starttls_auto=>false, :openssl_verify_mode=>1, :ca_file=>"/etc/ssl/certs/ca-certificates.crt"}
    irb(main):007:0> mailer.mail(from: 'xxxxx', to: 'xxxxx', 
    subject: 'test', body: "Hello, you've got mail!").deliver

I tried lots of combinations but nothing works.

I'm confused and i just wanted to know if there is a problem on client side or server side

Rails ActionMailer 6.1 / Ruby 3.1.2 / docker : certificate verify failed (self signed certificate)

0 Answers0