Hi Daphne,

Thanks for using Community Hub.

I wondered if you might be able to share the error message you encounter by reply, that should help us to narrow this down for you.

Regards,

Andy
Sage UKI

Sure

"Error with the address [email protected] : Unknown Error. Please check Windows Event Log for more details."

I have removed the email address which is correct because when I go to the older version of Outlook 365 it sends.

Thanks Andy.

Thanks Daphne. 

Are you using webmail or a desktop version of Outlook? If you're using webmail, you'll need to configure your SMTP settings, you can find out more about this here: Use webmail to email documents >

I'm using a desktop version of Outlook 365.

"I have to revert back to the older version of Outlook to send them, I keep getting an error message when I try to do it on Outlook 365 latest version. "

Are you using the "new outlook" from 365?

Getting started with the new Outlook for Windows - Microsoft Support

If you are, this currently doesn't work with Sage 50 Accounts. This version of Outlook is still a "preview" from Microsoft and has not yet been released.