Thunderbird suffers from an insane default. in your imap accout settings, you *must* set the folder sync size to the last 60 days (example) else TB will sync *all* of your mail. I blame dvelopers who live in "bandwidthless world". Look for this setting, I can't give exact info without a pc or TB.. <div class="gmail_quote">On May 10, 2012 6:19 PM, "Jan Greeff" <<a href="mailto:jan@verslank.net">jan@verslank.net</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> Thunderbird (especially when compacting folders) was causing my Ubuntu 12.04 to hang to the extent where all I could do was to switch off power and start over. I then reverted to Ubuntu 11.04 , but the same is happening here. I have about 1,1 gigabyte of e-mails in various folders, could this be the reason why this is happening? Jan -- ubuntu-za mailing list <a href="mailto:ubuntu-za@lists.ubuntu.com" target="_blank">ubuntu-za@lists.ubuntu.com</a> <a href="https://lists.ubuntu.com/mailman/listinfo/ubuntu-za" target="_blank">https://lists.ubuntu.com/mailman/listinfo/ubuntu-za</a> </blockquote></div>