Duplicated/Reappearing Email

Sometimes you'll find duplicated (2) copies of the same message, or messages that were previously deleted or moved into subfolders now reappear in Inbox folder. There are many possible causes. This memo covers only the 1 most common scenario.

This phenomenon will happen if all these conditions are met:

1. you're using POP server (as opposed to Exchange Server, etc.)
2. you set your email client (Outlook, etc.) to leave messages on mailbox for x days.
   • presumably to allow checking email at multiple workstations, or
   • use a mobile device to check live email (as opposed to slave sync.), or
   • you want to use webmail non-exclusively (with Outlook, etc.)
3. you setup a new workstation (or mobile device) to check email for the 1st time, and
   • instead of starting fresh, you brought with you the existing set of messages, via manual import, or Exchange Server caching mode auto sync.
   • the new station/device would have no knowledge of any previously download messages that are still existing on the mail server.
   • the newly re-downloaded messages will appear as duplicates, or reappearing if they were previously deleted or moved.

Why does it happen?

Standard Internet email (POP3 protocol) is designed for a simplistic consumer mode under the typical scenario of: 1 workstation checking against 1 server, w/o leaving messages behind. Any deviation from such scenario will result in glitches, as there are no provisions to accommodate such tricks/techniques as multi-station mixed mode. This is a 1-time occurrence. Things will return to normal after that initial mail check. Note: Exchange Server, on the other hand, is designed from ground up to accommodate such complex scenarios, with perfect coordination and tracking.

Recommended Remedy w/ Pre-planning (clean, reliable):

1. suppress send/receive when you setup that POP account
2. create a subfolder HoldInbox, move entire content of current Inbox to HoldInbox
3. trigger send/receive
4. Sort messages in Inbox by date, most recent on top
5. delete all duplicated message (select by date range) in 1 step
6. move back preserved message from HoldInbox to Inbox
7. resume normal send/receive on the POP account

Recommended After-The-Fact Remedy (messy, slightly risky):

1. Sort messages in Inbox by date, most recent on top
   • Duplicates are easy to spot, as they're adjacent to each other
2. Skip right past all the new messages and click on the first duplicated old message
3. repeat the sequence as needed
   •  Del   Down  (to delete the message and move to next), or
   •  Down  (to skip to the next message)
   • do this at a rapid pace but remain mindful
   • pause and undo last delete as soon as you notice the mistake
   • typically, the bold type (unread) ones are the ones you want to delete
   • it's a messy, tedious, but entirely feasible process

SEE ALSO:

• Exchange Server Modes
• Email Forwarding, as related to confidentiality
• SPAM Prevention
• Email Failed