Email test error with plugin ** SMTP Error could not connect to Host

Hi

URGENT help needed ..

We are having issues with SMTP. Installed your plugin and testing it. I know I have the correct credentials for SMTP here, correct email address, password and SMTP and Port. I have actually setup the email in Outlook and tested it firstly so I know 100% that I have the credentials correct. No SSL and Port 587.

First question, my client website is on my temporary server and I wanted to setup the SMTP working before the site goes live onto another server. Wanted to ask firstly whether that is going to cause an issue with my testing ?

So website currently is temporarily hosted on my demo website for client to upload images and products etc before going live. and SMTP will be through the Hosting Server that the Live Website will be in 1 week time.

There was a problem while sending a test email. Related debugging output is shown below:

I will be upgrading all plugins and Version of WordPress once most of inputting has been completed by client otherwise don’t want issues .

Help would be greatly appreciated as I have never used your plugin before.

Versions:
WordPress: 4.5.13
WordPress MS: No
PHP: 5.6.33
WP Mail SMTP: 1.2.5

Params:
Mailer: smtp
Constants: No
ErrorInfo: SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting
Host: mail.DOMAINNAME.COM.AU
Port: 587
SMTPSecure: string(0) “”
SMTPAutoTLS: bool(false)
SMTPAuth: bool(true)

Server:
OpenSSL: Yes
SMTP Debug:
2018-02-27 08:42:08 Connection: opening to mail.DOMAINNAME.COM.AU:587, timeout=300, options=array (
)
2018-02-27 08:42:08 Connection: opened
2018-02-27 08:42:12 SERVER -> CLIENT: 220-cp173.ezyreg.com ESMTP Exim 4.89_1 #1 Tue, 27 Feb 2018 19:42:12 +1100
220-We do not authorize the use of this system to transport unsolicited,
220 and/or bulk e-mail.
2018-02-27 08:42:12 CLIENT -> SERVER: EHLO mydemosite.com.au
2018-02-27 08:42:12 SERVER -> CLIENT: 250-cp173.ezyreg.com Hello TEMPDOMAINNAME.COM.AU [27.121.64.173]
250-SIZE 52428800
250-8BITMIME
250-PIPELINING
250-AUTH PLAIN LOGIN
250-STARTTLS
250 HELP
2018-02-27 08:42:12 CLIENT -> SERVER: AUTH LOGIN
2018-02-27 08:42:12 SERVER -> CLIENT: 334 VXNlcm5hbWU6
2018-02-27 08:42:12 CLIENT -> SERVER: c2FsZXNAeW91cmJlYXV0eXJvdXRpbmUuY29tLmF1
2018-02-27 08:42:12 SERVER -> CLIENT: 334 UGFzc3dvcmQ6
2018-02-27 08:42:12 CLIENT -> SERVER: VmFtb3VzYXM4MjY1
2018-02-27 08:42:14 SERVER -> CLIENT: 535 Incorrect authentication data
2018-02-27 08:42:14 SMTP ERROR: Password command failed: 535 Incorrect authentication data
2018-02-27 08:42:14 SMTP Error: Could not authenticate.
2018-02-27 08:42:14 CLIENT -> SERVER: QUIT
2018-02-27 08:42:14 SERVER -> CLIENT: 221 cp173.ezyreg.com closing connection
2018-02-27 08:42:14 Connection: closed
2018-02-27 08:42:14 SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting
Please copy only the content of the error debug message above, identified with an orange left border, into the support forum topic if you experience any issues.