Email sending broken after previously working

We have been using Manager Server Edition (purchased) and sending emails with no difficulty.
However, today we have started getting the Error: NameResolutionFailure.

This is preventing sending emails.
I have checked that the mail server is resolving correctly from the server and
have restarted manager in case there was an issue.
The mail server is up and functional and the credentials for SMTP auth have not changed.

Is there any way to further debug this issue?

You will need to upgrade to the latest version of server edition. The upgrade is free.

It would be good if this error provided a more specific error code.
It’s not good to be chasing DNS problems when there are none!

Fixed by upgrading, why did this stop working?

How do Mac desktop users upgrade the latest version? I’m having the same problem. “Free User”

Download the latest Mac version from Download | Manager. Open the disk image (.dmg) that downloads to your downloads location. Drag the Manager icon to your Applications folder. When asked, select whether to replace the old version or keep both version. That’s all. No need to uninstall anything.

Hi, I just update and it works but the option “send as Online PDF” is no more avalable, any idea ?!

That feature was removed from the program.