There are two basic protocols for email:
- POP3 - most prevalent. Email is downloaded from your server to your computer for you to manage. Unless you use WebMail (access email using a web browser), each device that accesses your email will download all messages that are new to that device. Deleting an email from one device does not mean that email is deleted from all other devices.
- IMAP - more likely to be seen in a corporate environment. Email is stored on the server. All email devices are accessing the same place for emails. Therefore, an email deleted from an email device deletes the email from the server.
If your email account supports only the POP3 protocol, you may be able to make your email account have a limited syncing ability.
- In Outlook, you can specify that email be removed from the server once it is downloaded. Unfortunately, this is not guaranteed 100% that once that email has been downloaded once, it will not be downloaded again because it depends on how long it takes to remove the email from being downloaded again before a different email device attempts to download it. Usually, you want all email devices to have a copy of all emails so you are not limited to where an email you want is stored.
- Outlook also has a setting to delete an email from the server once the deleted items folder is emptied. Again, you have a timing problem where an email may be downloaded to another email device before the deleted items folder is emptied.
