Not properly identifying/authorizing SMTP requests

[endigma]

Subject of the issue

vaultwarden's built in SMTP fails when sending emails on domains with strict DMARC.

Your environment (Generated via diagnostics page)

• Vaultwarden version: v1.21.0
• Web-vault version: v2.19.0d
• Running within Docker: true
• Uses a reverse proxy: true
• IP Header check: true (X-Real-IP)
• Internet access: true
• Internet access via a proxy: false
• DNS Check: true
• Time Check: true
• Domain Configuration Check: true
• HTTPS Check: true
• Database type: PostgreSQL
• Database version: PostgreSQL 13.3 on x86_64-pc-linux-musl, compiled by gcc (Alpine 10.2.1_pre1) 10.2.1 20201203, 64-bit
• Clients used:
• Reverse proxy and version:
• Other relevant information:

Config (Generated via diagnostics page)

{
  "_duo_akey": null,
  "_enable_duo": false,
  "_enable_email_2fa": false,
  "_enable_smtp": false,
  "_enable_yubico": true,
  "_ip_header_enabled": true,
  "admin_token": "***",
  "allowed_iframe_ancestors": "",
  "attachments_folder": "data/attachments",
  "authenticator_disable_time_drift": false,
  "data_folder": "data",
  "database_max_conns": 10,
  "database_url": "**********://***********:********************************@********/***********",
  "db_connection_retries": 15,
  "disable_2fa_remember": false,
  "disable_admin_token": false,
  "disable_icon_download": false,
  "domain": "*****://*****.********.**",
  "domain_origin": "*****://*****.********.**",
  "domain_path": "",
  "domain_set": true,
  "duo_host": null,
  "duo_ikey": null,
  "duo_skey": null,
  "email_attempts_limit": 3,
  "email_expiration_time": 600,
  "email_token_size": 6,
  "enable_db_wal": true,
  "extended_logging": true,
  "helo_name": null,
  "hibp_api_key": null,
  "icon_blacklist_non_global_ips": true,
  "icon_blacklist_regex": null,
  "icon_cache_folder": "data/icon_cache",
  "icon_cache_negttl": 259200,
  "icon_cache_ttl": 2592000,
  "icon_download_timeout": 10,
  "invitation_org_name": "** vault",
  "invitations_allowed": true,
  "ip_header": "X-Real-IP",
  "job_poll_interval_ms": 30000,
  "log_file": null,
  "log_level": "Info",
  "log_timestamp_format": "%Y-%m-%d %H:%M:%S.%3f",
  "org_attachment_limit": null,
  "org_creation_users": "",
  "password_iterations": 100000,
  "reload_templates": false,
  "require_device_email": false,
  "rsa_key_filename": "data/rsa_key",
  "send_purge_schedule": "0 5 * * * *",
  "sends_folder": "data/sends",
  "show_password_hint": true,
  "signups_allowed": true,
  "signups_domains_whitelist": "",
  "signups_verify": false,
  "signups_verify_resend_limit": 6,
  "signups_verify_resend_time": 3600,
  "smtp_accept_invalid_certs": false,
  "smtp_accept_invalid_hostnames": false,
  "smtp_auth_mechanism": null,
  "smtp_debug": false,
  "smtp_explicit_tls": false,
  "smtp_from": "*****@********.**",
  "smtp_from_name": "** vault",
  "smtp_host": "****.*******.***",
  "smtp_password": "***",
  "smtp_port": 587,
  "smtp_ssl": true,
  "smtp_timeout": 15,
  "smtp_username": "**********@****.*******.**",
  "templates_folder": "data/templates",
  "trash_auto_delete_days": null,
  "trash_purge_schedule": "0 5 0 * * *",
  "use_syslog": false,
  "user_attachment_limit": null,
  "web_vault_enabled": true,
  "web_vault_folder": "web-vault/",
  "websocket_address": "0.0.0.0",
  "websocket_enabled": false,
  "websocket_port": 3012,
  "yubico_client_id": null,
  "yubico_secret_key": null,
  "yubico_server": null
}

Steps to reproduce

Set up an email with properly configured DMARC/DKIM, attempt to send email on it using Vaultwarden.

Expected behaviour

Email should be signed and sent.

Actual behaviour

Email fails to reach its destination due to DMARC failure.

[paolobarbolini]

I also have my email setup with strict DMARC and everything is working as it should. I tried sending an email to https://www.mail-tester.com from the Vaultwarden Admin interface and every check passed.

Are you sure everything is configured correctly and enough time passed since you configured your email account?

[endigma]

I'm already able to send emails on this domain from the same server using Mailgun and Roundcube that pass all the checks at mail-tester. If I send mail from vaultwarden it fails because 'server is not authorized to send this message'. I believe I have to somehow provide vaultwarden with the necessary information to send emails on my domain.

[kennylajara]

Do you have Vaultwarden in the same domain/subdomain? If not, have you created MX records for the domain or subdomain hosting Vaultwarden?