Can't send emails via SMTP

Can't send emails via SMTP

I followed these instructions:

Zoho Mail SMTP server address: smtp.zoho.com
Zoho Mail SMTP user name: my_email@mydomain
Zoho Mail SMTP password: my password
Zoho Mail SMTP port: 465
Zoho Mail SMTP TLS/SSL required: yes


I get this error: 

  
   ["instantiate"]=> string(36) "Could not instantiate mail function." ["authenticate"]=> string(35) "SMTP Error: Could not authenticate." ["from_failed"]=> string(35) "The following From address failed: " ["recipients_failed"]=> string(45) "SMTP Error: The following recipients failed: " ["data_not_accepted"]=>my string(30) "SMTP Error: Data not accepted." ["connect_host"]=> string(43) "SMTP Error: Could not connect to SMTP host." ["file_access"]=>
  
  
   

  
I'm using Wordpress with WP-Mail-SMTP plugin.
PS: This software I am using works fine with Google Apps mail as well as my own SMTP servers