Have you ever noticed duplicate emails in Outlook? Sometimes a PST file may contain multiple copies of the same email message. A duplicate item can be anything, i.e. an email, contact, calendar, note, task, journal, or an attachment.
Below are the most common reasons which create duplicate emails in Outlook data file:
Generally, we receive a lot of email messages every day. And sometimes we may receive multiple copies of the same email message. Some companies send email messages (spam) regularly to promote their products and services. Since they’re auto-generated email messages, you may receive them more than one or multiple times. This will cause duplicate emails in the Outlook data file.
If you execute the synchronization process incorrectly or any interruption occurs during synchronization, it may cause duplicate emails in the Outlook mailbox.
Sometimes a fault in the mail server may create unwanted duplicate emails in Outlook. Make sure that you don’t activate the “Leave Messages on the Server” settings option.
If the configuration of Outlook rules is not performed correctly, this situation may lead to email duplication. Make sure the “Move a copy to” rule is applied only a single time to a particular email message, not two or more than two times.
If the process “merging PST files” is performed incorrectly, it may also result in duplication.
These are a few common reasons which may cause duplicate emails in Outlook. Having a large number of duplicate items may cause you great confusion. This will also increase the size of your mailbox day by day. And then a time will come a time when your mailbox size will reach its maximum size, i.e. 2 GB for ANSI PST and 20 GB for Unicode PST. This may cause some serious problems for Outlook users. A heavy mailbox can slow down your Microsoft Outlook client. You may also face corruption due to oversized PST files.
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Also, Read this blog:- Outlook Duplicate Items Remover