Known IMAP issues
My non-English labels are not displaying in Outlook 2003 or Outlook Express.
Most users should see all of the labels in their web interface replicated as folders in their IMAP client. However, if you are using an English version of Outlook 2002, Outlook 2003 or Outlook Express, but your web interface is set to a language that uses non-Latin characters, your folder names will not display properly. In addition, some subject and sender names may show as garbled text.
This is an issue with these versions of Microsoft Outlook. For more details, please contact Microsoft's customer service department.
I have thousands of messages and my email client is crashing.
Most desktop clients will perform poorly with large numbers of messages in a folder, or may even crash. The number varies from client to client and also depends on your machine's performance and memory. This limit can range from 20,000 messages to 100,000 messages. Considering Gmail's high quota for mail that can store well over 100,000 text messages, it's possible that your mail client will experience this problem, particularly in processing your '[Gmail]/All Mail' folder.
If you have this many messages in your labels, we recommend doing some housework to clean up your labels in the Web interface. Remember, the web interface shows counts of threads, not messages.
On the other hand, most mobile IMAP clients are designed for low bandwidth, and low memory/performance systems, and don't attempt to download all messages. If you only use IMAP from mobile clients, you probably don't have to change your current Gmail label habits.
My client is taking forever to download my messages.Many desktop email clients will attempt to download a limited set of information about every message in a folder (headers or index). Others will attempt to download all of the messages in a folder. Some will even attempt to download all of the messages in all of the folders. If you have a lot of messages, this can take a long time, and your IMAP client might not be usable until after it has finished this initial sync with the server. Future syncs should be faster.