I've been running Thunderbird on an IMac at work for over a year without any problems. Yesterday, I added an IMac so now there are 2 IMacs on the network. I downloaded and set up Thunderbird for the person using the added IMac without any problems. However, now, when Thunderbird checks for emails, if there is a message for her on the mail server, I get the mail and vice versa. I was checking her email settings, the alert sounded for new message, I checked her inbox and it was an email addressed to my account from a customer. I was later working on my computer when the new mail alert sounded. I looked in my inbox and 3 new emails came in. One address to her email address and 2 to my email address. What can I do to so that she receives emails addressed to her and I get my emails? IMacs are running OS 10.5.8 Thanks for any help.