郵件設定 Email Setting (POP) - 取消自動刪除伺服器內的電郵 Disable "Remove email from the server" option

MAC
1. Start the Mail program.

2. Open the “Preferences” window. Click Mail, then Preferences:

The preferences window will appear.

3. Choose the “Account Information” screen.

Navigate to the “Account Information” screen. To do this: 

• Click Accounts (the blue “@” sign) along the top of the window if necessary.
• Click the address@example.com account in the left “Accounts” column if necessary.
• Click Account Information if necessary.

4. Disable "Remove copy from server".
Uncheck "Remove copy from server after retrieving message". 

(The “Description” section doesn’t matter and may say something else, although it’s easier to keep track of multiple addresses if you set it to be the email address.)

5. Close the "Preferences" window and save the changes.

Click the red close button in the upper-left corner of the "Preferences" window. If the "Save Changes" dialog pops up, choose Save.

Outlook

1. Open Outlook.
    
2. Select File, then Info.
    
   
   
   
   
3. Click Account Settings. Select the email account (POP) then click Change. 
    
   
   
   
   
4. For Outlook 365. Tick "Leave a copy of messages on server". Do not tick Remove from server after X day(s).
    
   
   
5. For Outlook 2013 or 2010, please click More Settings…. 
   
    
6. Click Advanced.  Tick "Leave a copy of messages on server". Do not tick Remove from server after X day(s). 
    
   
   
7. Click OK then Next > and Finish. 

IPHONE (IOS 14.6) Default Mail app

1. 在 iOS 主畫面中按「設定」「Settings」。將目錄向下拉，點選「郵件」。
In iOS homepage, click "Settings". Scroll down and click "mail"

2. 點選「帳戶」，再按進你的電郵帳戶。
Click "Accounts", then click on your email account again.

3. 在POP3 設定 點撃「進階」。
Click "Advance" in POP account Setting.

4. 將以下項目改做"永不"。
Disable the email remove function.