Error When Upgrading To New Software

I've seen this error before but I can't remember how to solve this when upgrading the software:

ErrorMessage could not be sent.
Mailer Error: SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting

Hello

You should upload a new version of phpmailer

Best regards

Robert

Thanks!

Where and how do I get and do that?

Ask your server admin.