If you use 'POP' mail accounts then you can only access and download from the server 'Inbox' to the pop mail account Inbox. If you have selected to 'keep messages on server' option, then other PC's with POP (or IMAP )mail accounts can access the Inbox and download the same email. This will probably explain how you have managed to get same email downloaded to different computers. Sent emails will only be stored in the pop mail account 'Sent' folder of the mail account that sent the email. The sent emails are not stored on the server, so no other POP nor IMAP nor access via webmail can see any of those sent emails. Options in no particular order of preference. Create IMAP mail accounts: If you create new existing mail accounts, but this time create them as IMAP mail accounts, then all emails are stored on the server. IMAP mail accounts get a remote view of the server and can subscribe to see any folder on server. This means if you send email from one computer, the email is stored in server 'Sent' folder, so another IMAP mail account can also see server Sent folder contents. It also means if you delete an email via webmail or either imap maila ccount then that email will be deleted off server and disappear from all views as folders are sycnhronised. Keep POP mail account: When sending an email, always send yourself a copy, then the 'Sent' email will appear in the server 'Inbox'. This will get downloaded as new mail to either pop mail account, but will require moving to appropriate folder or deleting as required. Note: If you send just one email from the other Pop mail account, a 'Sent' folder will get automatically produced which you can then use. Profile in a shared folder: If the two PC are on a shared network then you could set up the Profile storage in a shared folder accessed by both PC's. http://kb.mozillazine.org/Sharing_profiles_-_mail