Issue: SMTP Ports Other Than 25 Not Working

[Mayank-Grorapid]

I am experiencing issues when trying to use SMTP ports other than port 25. I have tested both port 587 and port 465, but neither seems to work for email verification. The only port that functions correctly is port 25, which is typically blocked by many cloud service providers.

Since port 25 is not a viable option for email verification in most cloud environments, this limitation significantly impacts the usability of the library.

Steps to Reproduce:

1. Set up ping-email with the following configuration:

   import { PingEmail } from "ping-email";
   
   const pingEmail = new PingEmail({
       port: 587, // or 465
       fqdn: "smtp.example.org",
       sender: "[email protected]",
       timeout: 15000,
       attempts: 5,
       debug: true
   });
   

2. Call the ping method with a valid email address:

   const result = await pingEmail.ping("[email protected]");
   console.log(result);
   

3. Output:

   [ping-email - INFO]:  Pinging email: [email protected]
   [ping-email - INFO]:  Verifying syntax of email: [email protected]
   [ping-email - INFO]:  Verifying disposable domain of email: [email protected]
   [ping-email - INFO]:  Verifying domain of email: [email protected]
   [ping-email - INFO]:  Verifying SMTP of email: [email protected]
   [ping-email - INFO]:  Attempt 1 of 5
   {
     email: '[email protected]',
     valid: false,
     success: false,
     message: 'Connection timeout'
   }
   

• Any guidance on alternative configurations would be appreciated.