ESP8266 Wi-Fi module SMTP server problem

I was using ESP8266 Wi-Fi module with Arduino programming to send email using SMTP port 465. It has been working perfectly fine for the past few days. But when I try it today, it says "Cannot connect to mail server". Then I try with telnet to check on port 465 and it's not responding. When I try port 587, it does respond but my program in Arduino does not support port 587. So, I have to use port 465. I have allowed less secure apps and run the captcha as well. Still not working. Is there any way I can solve this problem.

Thank you!

Sounds like the email server is down. Are you using a domain name or an IP for the email server?