How to avoid mails getting downloaded many times in outlook in Linux Reseller Hosting Plan?

This article describes how to avoid mails downloading in outlook automatically again and again in Linux cPanel Server.

There are 2 possible reason for that, please refer the same as below,

i) If you have enabled “leave messages on the server” then Outlook remember what messages it has downloaded and keeps a list of the “message IDs” for the messages it has downloaded.When it checks for new messages, it gets a list of all the message IDs on the server, compares it to the list or message IDs it has downloaded, and requests the messages it does not have. If the list of downloaded message IDs becomes corrupted, which is common especially when that list gets long, Outlook will “lose track” and start downloading all messages over and over again in Linux Hosting Plan.

RESOLUTION: Un-check “leave messages on the server” and then “Send and receive” to get the mailbox cleaned out. You can then re-check it.

ii) Your e-mail client is automatically checking for new e-mail, too often Checking more frequently than every 10 to 15 minutes can result in the next check beginning before the last one has ended. When that happens, the index file of the e-mail client will no longer be synchronized with the e-mail server, resulting in multiple copies of the same message. Do the following to correct his issue:

RESOLUTION: Change the setting of your e-mail client so that it automatically checks for new e-mail no more frequently than every 15 minutes. You can manually force a check if needed, but be sure the last check has completely finished.