how can i detect net smtp authenticate error in golang?

Question

i am using gopkg.in/mail.v2 for sending email and i want to detect authenticate error for some reasons.

i want something like this:

if err := d.DialAndSend(m); err != nil {
        if errors.As(err, net.AuthenticateError{}) {
            //do something
        }
        return err
    }

but we don't have something like net.AuthenticateError.

is there any way to detect authenticate error for requests?

Answer 1

Unfortunately, the gopkg.in/mail.v2 package does not provide a specific error type net.AuthenticateError for authentication errors. To detect authentication errors, you may need to inspect the error returned by d.DialAndSend(m) and check if it contains any relevant information indicating an authentication failure.

Typically, authentication errors in email sending can be caused by incorrect credentials, SMTP server configuration issues, or network connectivity problems. It is important to handle these errors appropriately to provide meaningful feedback or take necessary actions.

Here's an example on how you can handle authentication errors when using gopkg.in/mail.v2:

if err := d.DialAndSend(m); err != nil {
    // Check if the error message contains information about authentication failure
    if strings.Contains(err.Error(), "authentication failed") {
        // Handle authentication error here
        // do something
    }
    return err
}

In this example, we are checking if the error message string contains the phrase "authentication failed". You can modify the check based on the specific error message or pattern you observe when authentication fails in your use case.

Remember to import the necessary packages, including strings, and ensure you handle other potential error scenarios as needed.