Use IMAP instead of POP to retrieve emails
I am having a problem with duplicate e-mails. I used to have Mac Mail set up on my iPhone and then a POP set up in my Mac Mail desktop. Now, I have a Macbook Pro, so I set up the Mac Mail, but it set it up with an IMAP. It's a disaster! I have about 15 copies of every e-mail I send and receive. I put them in the trash, and when I search for something the ones in the trash come up as well as sent mail, all mail, it's a disaster. How can I fix this? I wish I could just go back to POP and just re-check the e-mail rather than have this duplicate e-mail situation on my laptop.
I finally found the answer to this dubious multiple duplicate emails problem for the 'Mail' app.
Well it worked for me anyway. Instead of using POP, use IMAP to retrieve emails from the server.
I had to remove/delete the mail account first then recreate it. Where the application automatically uses POP in the drop down, change it to IMAP. The rest is based on your login information.
Hope this helps.
Below is an excerpt from this link:
http://help.joyent.com/index.php?id=67&pg=kb.page
IMAP vs. POP
The basic difference between IMAP and POP3 is that with POP3 you work most of the time offline because you only connect to the server to download new mail to your computer. This means you have to check your server mailbox periodically. Access from multiple computers/clients is possible by leaving your new mail on the server, but problematic.
IMAP, on the other hand, allows you to always work with your mail live on the server. This means that a connection is made and typically maintained through your entire email session. To save bandwidth,
messages viewed once are cached on your computer and you can also set up synchronization to store permanent copies of messages locally. Second,
IMAP allows you to work with an unlimited number of folders, which can be nested, all of them being stored on the server, always accessible from any computer in the world. This allows to shift all email filters and Spam handling to your email server (see Procmail and Spamassassin).
Basically, IMAP is recommended for a modern email use, unless contraindicated by very special circumstances (e.g. a limited and expensive Internet connection). ###