package email import ( "fmt" "net" "regexp" "strings" "github.com/resend/resend-go/v2" ) type Email struct { From string To string Subject string Text string Html string APIKey string } func SendEmail(email Email) error { client := resend.NewClient(email.APIKey) _, err := client.Emails.Send(&resend.SendEmailRequest{ From: email.From, To: []string{email.To}, Subject: email.Subject, Text: email.Text, Html: email.Html, }) if err != nil { return fmt.Errorf("error sending email: %w", err) } return nil } func IsValidEmail(email string) bool { // Basic length check if len(email) < 3 || len(email) > 254 { return false } // Regular expression for email validation (RFC 5322 compliant) pattern := `^[a-zA-Z0-9.!#$%&'*+/=?^_\x60{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$` // Compile regex regex := regexp.MustCompile(pattern) // Check if email matches regex pattern if !regex.MatchString(email) { return false } // Split email into local and domain parts parts := strings.Split(email, "@") domain := parts[1] mx, err := net.LookupMX(domain) if err != nil || len(mx) == 0 { return false } return true }