thunderbird problem

prije 2 tjedna sam slozio 5 mailova u TB. i svi su radili. sad samo s gmaila mogu slati mailove. s ostalih ne mogu.
kad šaljem s sluzbenog javi ovu grešku: "An error occurred while sending mail. The mail server responded: This mail server requires authentication when attempting to send to a non-local e-mail address. Please check your mail client settings or contact your administrator to verify that the domain or address is defined for this server.. Please check the message recipient xxxxxxx@gmail.comSand try again."

probavao sam svašta ali ne uspijeva...
pomozite... :/