SMTP Error: Could not authenticate

The [email protected] inbox is setup using Office365.
When I fill out any of the contact form on the Contact Us page and hit Submit, it does not send. The WP Mail SMTP settings are correct. I am using:
From Email: [email protected]
SMPT Host: smtp.office365.com
SMTP Port: 25
Encryption: None
Authentication: On
SMPT Username: [email protected]
SMPT Password: (what ever the password is)

When I click on the Email Test tab and send a test email, I get the following error message:

Versions:
WordPress: 4.9.1
WordPress MS: No
PHP: 7.0.27
WP Mail SMTP: 1.2.4

Params:
Mailer: smtp
Constants: No
ErrorInfo: SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting
Host: smtp.office365.com
Port: 25
SMTPSecure: string(0) “”
SMTPAutoTLS: bool(false)
SMTPAuth: bool(true)

Server:
OpenSSL: Yes
SMTP Debug:
2018-02-02 10:09:58 Connection: opening to smtp.office365.com:25, timeout=300, options=array (
)
2018-02-02 10:09:58 Connection: opened
2018-02-02 10:09:58 SERVER -> CLIENT: 220 LNXP265CA0024.outlook.office365.com Microsoft ESMTP MAIL Service ready at Fri, 2 Feb 2018 10:09:57 +0000
2018-02-02 10:09:58 CLIENT -> SERVER: EHLO https://www.gorillascaffolding.com
2018-02-02 10:09:58 SERVER -> CLIENT: 250-LNXP265CA0024.outlook.office365.com Hello [77.104.173.38]
250-SIZE 157286400
250-PIPELINING
250-DSN
250-ENHANCEDSTATUSCODES
250-STARTTLS
250-8BITMIME
250-BINARYMIME
250-CHUNKING
250 SMTPUTF8
2018-02-02 10:09:58 SMTP Error: Could not authenticate.
2018-02-02 10:09:58 CLIENT -> SERVER: QUIT
2018-02-02 10:09:58 SERVER -> CLIENT: 221 2.0.0 Service closing transmission channel
2018-02-02 10:09:58 Connection: closed
2018-02-02 10:09:58 SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting

I was advised Salva to do the following:
1) Update the plugin to the latest version.
2) Contact your hosting support

You might need to change the SMTP Host to some kind of relay (hosting should you provide all the correct values, ask them).

I contacted the hosting company and this is what they said:
I checked your case and it seems that the WP mail SMTP plugin cannot establish connection due to incorrect login details:

Code:
2018-02-01 13:56:10 SMTP Error: Could not authenticate.
2018-02-01 13:56:10 CLIENT -> SERVER: QUIT
2018-02-01 13:56:10 SERVER -> CLIENT: 221 2.0.0 Service closing transmission channel
2018-02-01 13:56:10 Connection: closed
2018-02-01 13:56:10 SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting

However, I managed to successfully login into your office365.com account with the same username and password.

I also verified that the connection towards smtp.office365.com can be established via port 25:

Code:
bigbears@uk38 [~]# telnet smtp.office365.com 25
Trying 40.101.73.162…
Connected to smtp.office365.com.
Escape character is ‘^]’.
220 DB6PR07CA0170.outlook.office365.com Microsoft ESMTP MAIL Service ready at Thu, 1 Feb 2018 13:41:30 +0000

I reviewed the settings of your SMTP plugin and I would like to confirm that they are properly configured.

What I can recommend you in this case is to either re-install the WP mail SMTP plugin or use another one with similar functionalities

Please verify the results on your end and let us know if we can be of further assistance.

I’m not sure what to do now. I have tried installing another plugin and i get the same error on that too…
CLIENT -> SERVER: EHLO https://www.gorillascaffolding.com
SMTP Error: Could not authenticate.CLIENT -> SERVER: QUIT
SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting

Can someone please help thanks.

Thanks

The page I need help with: [log in to see the link]