POS system could not retrieve TLS certificate for smtpout.secureserver.net:25

[JimGannon]

One of our customers reported she was not receiving her e-receipts from our POS system (which sends them to customers who opt out of printed receipts). Looking through the logs of our POS system, I see it is repeating this error many times over the last several weeks....

Could not retrieve TLS certificate for smtpout.secureserver.net:25

What can I do to fix this issue, our POS system only lets us set the SMTP Server, the SMTP Port, a 60-second Timeout, and the User Name and Password (of the email account we are trying to send from/through). 

Our POS support wrote:   This is likely because you have the email server settings set to use port 25. When we send out e-receipts we use opprotunistic TLS, which means we try to send TLS first and if we cannot we fall back to an unencrypted protocol. GoDaddy has port 25 set to an unencrypted protocol, which is standard practice. If you want to try and use their TLS enabled port then change the setting in WebOffice to use port 587. 

I have tried using smtpout.secureserver.net, smtp.secureserver.net, outlook-namcentral.office365.com, smtp.office365.com and dedrelay.secureserver.net  and all on ports 25, 465, 587, 3535 to no avail.

Any idea how I can get TLS used properly?

[JimGannon]

Could not retrieve TLS certificate for smtpout.secureserver.net:25

What can I do to fix this issue, our POS system only lets us set the SMTP Server, the SMTP Port, a 60-second Timeout, and the User Name and Password (of the email account we are trying to send from/through). 

Our POS support wrote:   This is likely because you have the email server settings set to use port 25. When we send out e-receipts we use opprotunistic TLS, which means we try to send TLS first and if we cannot we fall back to an unencrypted protocol. GoDaddy has port 25 set to an unencrypted protocol, which is standard practice. If you want to try and use their TLS enabled port then change the setting in WebOffice to use port 587. 

I have tried using smtpout.secureserver.net, smtp.secureserver.net, outlook-namcentral.office365.com, smtp.office365.com and dedrelay.secureserver.net  and all on ports 25, 465, 587, 3535 to no avail.

Any idea how I can get TLS used properly?