Cannot get multiple computers using EM Client to sync their Sent Messages

Cannot get multiple computers using EM Client to sync their Sent Messages, its only showing sent emails that were sent from each individual device.

What mail service are you using with your eM Client and are you using imap or pop protocol?

Using Gmail - I think I am using imap?

You have to save sent mail to Gmail’s online sent folder, not to your computers local sent folder. In eM try going to Tools>Accounts>IMap Tab (in the Account in question). Under “Special Folders” – is “Automatically detect special folder names” checked? If yes, then does the “Sent:” line specify “[Gmail]/Sent Mail”?