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 manager.io 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.
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.