cPanel accounts unable to use SMTP Send connectors

[DevTeam9200]

Also all our wordpress sites can not use SMTP send connectors to send email. I have contacted the hosting provider vultr and they advised they have unblocked smtp and should be working. but still we receive these errors:

Versions:
WordPress: 4.9.2
WordPress MS: No
PHP: 5.6.33
WP Mail SMTP: 1.2.4

Params:
Mailer: smtp
Constants: No
[Removed Due To Inclusion of Real URL]

We are using WHM / Cloud linux and no luck from cPanel support. It is not a smtp issue because regardless of smtp server i use same error.

Also when logging into the WHM admin panel it shows the SSL certificate for the whm.xxxxxx.xxx in use as expired and not using secure 2048 key size?


the hosting provider vultr advised the issue may be the ssl cert is not properly configured for the host and SMTP server on the server?

 

[cPanelMichael]

Hello,

The most common reason for the rejected SMTP connection to the remote server is the "WHM >> SMTP Restrictions" option. This feature prevents users from bypassing the mail server to send mail, a common practice used by spammers. Do you have root access to this server? If so, you'd need to disable this option if you want to allow that behavior.

Thank you.