This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Buscar en Ayuda

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Why is composing messages suddenly painfully slow?

more options

Composing email messages in Thunderbird has suddenly become painfully slow. Rebooting my computer (iMac running OS X Yosemite) and uninstalling and reinstalling Thunderbird has not helped. When I type words into the message window, I can't see what I did until I hit command ` twice to go to the main window and back to the message window. This makes it take a very long time to compose even a simple message to send.

Composing email messages in Thunderbird has suddenly become painfully slow. Rebooting my computer (iMac running OS X Yosemite) and uninstalling and reinstalling Thunderbird has not helped. When I type words into the message window, I can't see what I did until I hit command ` twice to go to the main window and back to the message window. This makes it take a very long time to compose even a simple message to send.

Todas las respuestas (1)

more options

Not a Yosemite Expert but that appears to be a focus-stealing issue on Mac OSX itself. The clicking _ ` _ is manually refocusing the 'main window' which I'm understanding from your post to be the ``Compose Window`` but as to why it is lagging does not seem to be Thunderbird's cause, consider looking at disk i/o during a replication session, and/or with a clean profile:

Clean profile being you copy/backup your present config `folder` and move outside its present directory and reload. If it persists it's not a user config issue if not it is something in your present config that has corrupted or misconfigured itself.