SMTP Verification Fails in Docker with "Connection refused (os error 111)"

SMTP Verification Fails in Docker with "Connection refused (os error 111)"

Description

When running the backend server inside a Docker container, SMTP-based email verification fails with the following error:

"message": "Connection refused (os error 111)"

This occurs while attempting to verify email reachability.

Steps to Reproduce

1. Run the backend service inside a Docker container
2. Trigger email validation for a Gmail address (e.g., [email protected])
3. Observe the validation response

Expected Behavior

• SMTP verification should successfully connect to the recipient mail server
• is_reachable should return a definitive value (true or false)

Actual Behavior

• SMTP connection fails with:

  复制

  Connection refused (os error 111)

• is_reachable is returned as "unknown"

Relevant Output

"smtp": {
  "error": {
    "type": "IOError",
    "message": "Connection refused (os error 111)"
  }
}