Lately, I've noticed my Thunderbird client on both my home & work PCs experiencing slowness where my entire PC seems to slow, the Thunderbird client window goes non-responsive. I currently run about 10 IMAP email accounts in the client, some of which are shared with other users. The mail server has not changed in the past several years. I also noticed I'm getting 3 script errors, not sure if this is related to my problem above: chrome://messenger/content/mail-offline.js:34 chrome://messenger/content/selectionsummaries.js:176 chrome:/ /messenger/content/folderpane.js.2001 Also, I noticed that the status/activity notes on the bottom left corner of the client constantly states "downloading xxxx of xxxxx in folder xxxx". Is this abnormal and would this slow down performance? If so, can I do anything to make sure my client is synced fully with the mail server so performance isn't affected. Thanks David