SMTP doesn't send an email from Drupal 8

Hello, 

I'm working on Drupal 8, PHP -7.0. I have installed the latest version of SMTP module which throws a below error when trying to send an email. 

• SMTP module is active.
• A test e-mail has been sent to xxxxxxx@xxxxxxx.com via SMTP. You may want to check the log for any error messages.
• The configuration options have been saved.

Warning message

Disabled fields are overridden in site-specific configuration file.

Error message

Unable to send email. Contact the site administrator if the problem persists.

I'm using the below configuration and entered the correct username and password

SMTP SERVER 

smtp.gmail.com

SMTP port: 465

Use encrypted protocol: SSL

Hostname: 

smtp.gmail.com

The below error in the logs:

Error sending email (from admin@xxxxx.com to xxxx@xxxxxxx.com with reply-to not set).

Help is appreciated. 

Thanks in advance!

Hello, 

I'm working on Drupal 8, PHP -7.0. I have installed the latest version of SMTP module which throws a below error when trying to send an email. 

• SMTP module is active.
• A test e-mail has been sent to xxxxxxx@xxxxxxx.com via SMTP. You may want to check the log for any error messages.
• The configuration options have been saved.

Warning message

Disabled fields are overridden in site-specific configuration file.

Error message

Unable to send email. Contact the site administrator if the problem persists.

I'm using the below configuration and entered the correct username and password

SMTP SERVER 

smtp.gmail.com

SMTP port: 465

Use encrypted protocol: SSL

Hostname: 

smtp.gmail.com

The below error in the logs:

Error sending email (from admin@xxxxx.com to xxxx@xxxxxxx.com with reply-to not set).

Help is appreciated. 

Thanks in advance!