Hi, I have a coworker who is having an issue with Mail that I am trying to troubleshoot for him. I'm definitely more of a Windows guy than an OSX guy so forgive me if I've skipped any obvious steps. So basically what is happening is anytime he tries to send a message from one of his accounts the message just disappears. There is no "woosh" sound, the message does not go into the Outbox, nothing, it's just gone. I've tried deleting and recreating his accounts and setting up accounts of mine on his system and get the same thing. I have already repaired permisssions and rebuilt the mail database. I did find a thread on here the other day with someone who had a similar problem, I can't seem to find the thread anymore but I think the final resolution was that they had to delete the Mail app and reinstall it from the DVD that came with their system. The problem is that this person got the computer second hand and it did not come with the original DVD. He is running OSX 10.7.5. If I download the 10.7.5 update will I be able to reinstall the Mail app from that somehow? I don't want to delete the app without knowing if I'll be able to reinstall it! Any other course of action I should take? Any help is much appreciated!