Title. Thunderbird is a really cool client but it's pretty slow. I blame that on the thousands upon thousands of emails that my hotmail and gmail each hold. I don't necessarily want to delete these emails, but I have seldom a reason to have any email older than 2 months in my thunderbird client slowing and crashing the program whenever I want to combine inboxes. To this end I went to "Synchronization & Storage" and told it to "Synchronize the most recent 2 months" but it didn't delete the huge cluster of older emails. The next option is to tell TB to delete these emails in the same menu but as I understand it that would also delete them in the server, which I don't want to do for posteriority. What do I do?