On one of my accounts I continually loose old messages, as of today the oldest is dated 4th Dec 2016, all my other accounts date back to 2010
I have been using Thunderbird IMAP for the past 10 years for several email accounts, four of which are on the same server. All the accounts have the same server settings. Over the past year, my most important account looses old messages. None of the other accounts have this problem. I could manage when messages older than 10 months went missing, but not when messages older than 2 weeks disappear. The Archive folders are no help with many gaps.
This is now at a crisis point.
I have been using Thunderbird IMAP for the past 10 years for several email accounts, four of which are on the same server. All the accounts have the same server settings. Over the past year, my most important account looses old messages. None of the other accounts have this problem. I could manage when messages older than 10 months went missing, but not when messages older than 2 weeks disappear. The Archive folders are no help with many gaps.
This is now at a crisis point.