We have a complex deployment of exchange, two Front end and two backend Microsoft Echange 2007 servers. Mail boxes are all stored in a SAN, and authentication is being done using two Active Directory servers.Everything was fine, until domain admin made some permission modification without notification. She is fired after restoring those setting back, but we are still in trouble with sending emails through OWA.We can send and receive emails via Outlook facing no trouble, but in OWA (using webmail), emails are not sent. They are just going to Draft folder and can not be deleted from Draft folder. Emails are received in OWA without any problem.

Same issue as belowin the forum:owa not send mailhttp://social.technet.microsoft.com/Forums/en-US/exchangesoftwareupdate/thread/b62d443e-ad62-4d71-8992-48db5072b11c