See also POP vs. IMAP or Why I Use IMAP

Being able to have all your mail clients display and use the same server-side IMAP folders is a wonderful thing, but one of the downsides is that every device/client does things a little differently. Some use the IMAP deleted flag, some use a “Trash” folder, others use “Deleted Items” (Outlook’s default). “Sent” is almost as bad: most clients use “Sent”, but many use “Sent Items” (Outlook’s default).

Mobile devices can usually be configured as POP or IMAP clients. If mobile devices are configured as POP accounts, you will not see Sent or Trash (deleted) items show up in your IMAP folders. If you want to see consolidated Sent and Trash items in your IMAP folders, use IMAP on all your other mail clients.

Webmail programs are virtually always IMAP clients and will see the same messages and folders as all other IMAP clients.

By default, the Thunderbird mail client only checks the Inbox folder for new messages. If you use multiple mail clients, Thunderbird may not automatically see messages that have been manipulated/moved by another mail client. There are two easy ways to deal with this:

In Thunderbird, to add a particular folder to the list of folders checked for new mail, you can:

Right-click on a folder (such as Trash or Sent) → Properties → Select 'When getting new messages, include this folder

To get Thunderbird to check all folders for new messages, you can make a configuration change to check all folders for new messages, but there are performance impacts.

Changing this setting to TRUE can negatively affect Thunderbird performance. This option may not be a good fit for users with large mail stores, a slow Internet connection or a slow PC.

Tools → Options → Advanced → Config Editor (button) → mail.check_all_imap_folders_for_new → TRUE

To set Thunderbird to check for new messages in all of your IMAP folders:

1. In Thunderbird, choose Tools → Options
2. In the Advanced tab, click Config Editor
3. Search for the preference mail.check_all_imap_folders_for_new
4. Set the preference to TRUE
   • Double-click on the settings to toggle the value between TRUE and FALSE

Mobile devices generally have fewer settings for Sent, Draft and Trash folder selections. For example, on one modern Android phone, you are not able to choose these folder settings at all.

Android default folder names for sent, draft and deleted items match the Thunderbird defaults:

Apple iOS devices like the iPad or iPhone appear to be more flexible, but their default settings may require tweaking for your needs:

To see Sent/Draft/Trash items in your IMAP folders, modify the settings to point to the corresponding folders on the server.

To modify the Sent/Draft/Trash folders on the iPhone:

1. Start at the home screen
2. Go to Settings
3. Choose “Mail, Contacts, Calendar”
4. Select an IMAP account
5. Scroll to the very bottom of the list, choose “Advanced”
6. Change each of the “Mailbox Behaviors” items as needed