SMTP Error - 530 From/Sender name is not valid.'

[f0sh]

I recently set up postalserver in a isolated environment. I want to send emails from another host inside this network to postal. However I always get the error.

Error sending email Error: Message failed: 530 From/Sender name is not valid
    at SMTPConnection._formatError (/app/node_modules/nodemailer/lib/smtp-connection/index.js:790:19)
    at SMTPConnection._actionSMTPStream (/app/node_modules/nodemailer/lib/smtp-connection/index.js:1706:34)
    at SMTPConnection.<anonymous> (/app/node_modules/nodemailer/lib/smtp-connection/index.js:1174:22)
    at SMTPConnection._processResponse (/app/node_modules/nodemailer/lib/smtp-connection/index.js:969:20)
    at SMTPConnection._onData (/app/node_modules/nodemailer/lib/smtp-connection/index.js:755:14)
    at SMTPConnection._onSocketData (/app/node_modules/nodemailer/lib/smtp-connection/index.js:193:44)
    at Socket.emit (node:events:517:28)
    at addChunk (node:internal/streams/readable:368:12)
    at readableAddChunk (node:internal/streams/readable:341:9)
    at Readable.push (node:internal/streams/readable:278:10) {
  code: 'EMESSAGE',
  response: '530 From/Sender name is not valid',
  responseCode: 530,
  command: 'DATA'
}

If I use Mailhog instead in the same environment, the message is sucessfully received.
The email sent has the following header:

From: no-reply@otherdomain.tld
To: some-email@example.org

The sender is configured to use the following SMPT configuration:

      - SMTP_HOST=postal-smtp-1
      - SMTP_PORT=25
      - SMTP_SECURE=false
      - SMTP_USER=<user>
      - SMTP_PWD=<secret>
      - NOREPLY_EMAIL="no-reply@otherdomain.tld"
      - SUPPORT_EMAIL="support@domain.tld"

And I can see, that for the postalserver mailserver the SMTP credentials are working and the SMTP server got accessed. I also added otherdomain.tld as a domain there. Postalserver cannot access the internet and at the current state also shouldn't.

My configuration looks like

version: 2

postal:
  web_hostname: mailer.domain.tld
  web_protocol: https
  smtp_hostname: mailer.domain.tld

main_db:
  host: mariadb
  username: postal
  password: <secret>
  database: postal

message_db:
  host: mariadb
  username: postal
  password: <secret>
  prefix: postal

smtp_server:
  default_port: 25
  default_bind_address: 0.0.0.0
  default_health_server_port: 9091 # The default port for the SMTP server health server to listen on
  default_health_server_bind_address: 0.0.0.0 # The default bind address for the SMTP server health server to listen on
  # Enable TLS for the SMTP server (requires certificate)
  tls_enabled: false
  # The path to the SMTP server's TLS certificate
  tls_certificate_path: $config-file-root/smtp.cert
  # The path to the SMTP server's TLS private key
  tls_private_key_path: $config-file-root/smtp.key
  # Override ciphers to use for SSL
  tls_ciphers: 
  # The SSL versions which are supported
  ssl_version: SSLv23
  # Enable proxy protocol for use behind some load balancers (supports proxy protocol v1 only)
  proxy_protocol: false
  # Enable connection logging
  log_connections: false
  # The maximum message size to accept from the SMTP server (in MB)
  max_message_size: 14
  # A regular expression to use to exclude connections from logging
  log_ip_address_exclusion_matcher: 

dns:
  # Specify the DNS records that you have configured. Refer to the documentation at
  # https://github.com/atech/postal/wiki/Domains-&-DNS-Configuration for further
  # information about these.
  mx_records:
    - mx1.mailer.domain.tld
  spf_include: mailer.domain.tld
  return_path_domain: mailer.domain.tld # The return path domain is the default domain that is used as the MAIL FROM for all messages sent
  route_domain: mailer.domain.tld # receive incoming e-mail by forwarding messages directly to routes in Postal
  track_domain: mailer.domain.tld # the domain for the links in emails to track clicks

smtp:
  # Specify an SMTP server that can be used to send messages from the Postal management
  # system to users. You can configure this to use a Postal mail server once the
  # your installation has been set up.
  host: 127.0.0.1
  port: 25
  username: # Complete when Postal is running and you can
  password: # generate the credentials within the interface.
  from_name: Mailer
  from_address: technik@domain.tld

web_server:
  default_port: 5000
  default_bind_address: 0.0.0.0
  max_threads: 3

worker:
  default_health_server_port: 9090
  default_health_server_bind_address: 0.0.0.0
  threads: 2

rails:
  secret_key: <secret>

I don't know what I have configured wrong, so that it is not working. Has someone a hint or an idea what there could be the error?
Thanks.

[willpower232]

530 From/Sender name is not valid

this usually occurs when the domain used hasn't been set up in the same server (or organisation) within Postal as the credential so you need to make sure the domain name you're trying to send with has at least been added to Postal in the same place as the credential

[f0sh]

Hey @willpower232,

maybe my post was too detailed or I didn't write it clear enough: I added the sender domain to the domain list of the same mailserver for which I also used the credentials.

[willpower232]

well clearly Postal disagrees otherwise it wouldn't have the error haha

the only other thing you should double check easily is the username, did you use the organisation/server username Postal shows on the SMTP details page?

[f0sh]

Yeah, that's why I don't get further with this problem. Obviously there is some other problem, which I cannot figure out.

The mailserver of the organisation I added is only having one credential and it says "Used about 5min ago". So I assume it went to the correct Organisation and Mailserver where I added the domain which is used as the FROM address. As I didn't get an authentication error I assume, the credentials were able to be used correctly. It's just the mailserver does not accept my mail I would like to deliver.

[willpower232]

I wonder then if the message body you're using contained a slightly different from address and maybe it confused things? You could have a look at the SMTP logs and see what its doing precisely.