Send email function suddenly stopped working

The send function of email through PCs stopped working on September 26. This is for 2 x me.com accounts, on 3 x PCs (Windows 7 (Outlook 2010); Vista (Mail) and XP (Outlook)). Can still send through iPhone; iPad and in the Cloud. Tried checking all settings, nothing has changed. Message comes up as "Encrypted Connection not available".

I disconnected my account through Outlook 2010 and tried to re-connect. This is now not happening at all.

Suggestions please