Outlook 2016 POP3 Duplicate Download of Email

Hello, I'm having terrible trouble with Outlook 2016 (Office 2016 Home and Small Business).

I use a POP 3 mail server and all the way through using Outlook 2003, everything worked perfectly. Obviously that was end of life so I decided to upgrade to Office 2016. I uninstalled Office 2003, then installed Office 2016. I then opened Outlook 2016 and set it to use the old PST file. This worked in as much as it brought in the old emails, but it also duplicated the downloads of emails so each time I opened Outlook, the same emails were being downloaded again such that I could end up with over 10 of the same mail.

I read somewhere that it could be because I used the old PST. I then went into mail and created a new profile, and started afresh. I still have the same issue. I've this morning updated Office to the latest version, and still the same. Please, please can anybody make any suggestion as to what I could try to eradicate this duplicate download problem? I'd be so grateful (so would my GP, I'm sure my blood pressure would drop substantially!).

If any further info required, please let me know

Thank you to any and all

Does your mail server support IMAP, or is it POP3 only? If your mail server supports IMAP, I suggest that you switch to IMAP - it's a much better protocol.

I have been through the same process as you, but have not seen any duplicate of emails. This tends to suggest you are not deleting emails from the server once POP3 has read them all. Could you have multiple versions of Outlook installed and running at the same time? Make sure you have removed the old version or you have deleted the email account in the old version.

As David_W suggests. Change to IMAP4. I have also done that as its more efficient. I also kept the PST format the same as you.

Post deleted by RobertoS

In reply to a post by David_W:

If your mail server supports IMAP, I suggest that you switch to IMAP - it's a much better protocol.

But not "better" if one wishes to automatically move all their email from the server to local storage. Whilst the growth of mailbox sizes makes this less of a necessity, there are still plenty of people who wish to operate their email in this way, and IMAP is not suited for it.

Who is your email provider & how many a/c's, even for diff aliases, have you set up for it in OL 2016?

Hi, not sure I understand that as an answer as I do just that with IMAP onto a PC.

I had been using POP3 for 3-4 years from both win PC's and android devices. The Android device was told to read and then leave the content, while the PC was told to read and remove the content from the server. When Android 6 came out with the associated gmail app, it did not always work so the same emails were downloaded again & again and again, consuming all of my ISP allowance. I then moved to IMAP on both Android & PC and all was well again. Could not get the Android POP3 gmail client fixed.

In reply to a post by iand:

Hi, not sure I understand that as an answer as I do just that with IMAP onto a PC.

Note I wrote the word "move" in bold. If you are purely using IMAP then the mail is copied from the server to the clients, but it isn't being moved (deleted from the server).

I have the same problem with duplicate emails being downloaded from the BT server onto my pc. On 20 April 2017, while using Windows Live Mail, duplicate mails started appearing in my pc Inbox and although I shut down, when I started up next day, there were over 500 duplicate emails that I'd previously downloaded and opened or deleted.
As this previously happened in Spring 2016, I contacted BT. I was told that the Yahoo server is sending another copy to a POP application, but the operator could give no explanation of any changes at BT which caused the problem on the specific date and to emails received between July 2016 and 20 April 2017. He said to put this message on the forum to bring it to the attention of others.
It is really time-consuming to delete so many duplicate emails.

If you want to keep the emails on the server, use IMAP instead of POP3. If you don't want to keep the emails on the server, stick with POP3 and untick "Leave a copy of messages on server".