New here the title says it all
Go to Menu > Tools > Operations and see if there are any SMTP errors in the Log tab.
In the mean-time, a common issue with sending is that the anti-virus/firewall application is at fault. Completely disable that as a test and see if you can send.
Otherwise, give the name of your email provider, and I will give you the best setting to use.
Thanks for replying but I think I have inadvertantly fixed problem by fixing authentication. I am using your program as Microsoft no longer supports Windows Live Mail. Can you tell me if this program gets updates like everything else? I am very happy with it at moment. Regards Greg
By “gets updates like everything else” I assume you mean the application updating to the most recent version.
Yes, it should check and let you know if there is an update, and you can choose to install it or not. The Release History also lists all recent updates, so you can also download directly from there if that is more convenient.