Thunderbird 140.4.0 / Win11Home 24H2 For many years now I have had several email accounts 'share' Thunderbird's Global Inbox (Local Folders) and this has worked fine (by the way I'm using POP throughout). For a long time I have also had a separate email account (call this account A) using its own Inbox. Again, all has been working fine. Very recently I created a new account (Account B) and directed this to use Account A's Thunderbird inbox (via Account B's Server Settings, Advanced...) and selected the "Include this server when getting new mail" option. All looked fine at that stage (I did not think to go back and check Account A's Server Settings, Advanced...). Under Account B's Copies and Folders I also directed Account B to use Account A's folders. As I expected, Account B did not have any of its own folders created. On selecting Account A in the folder pane and checking for emails (via the Get messages icon at the top of the folder pane), only Account B was checked (as evidenced by the status bar messages scrolling through at the bottom of the window). This was most perplexing - had I somehow lost a whole bunch of messages that I knew should be sitting in the inbox at the mail server? However, I soon found the culprit. Account A's Server Settings, Advanced.... were completely greyed out (and so effectively disabled) - see image attached. So setting up a 2nd email account to download to 1st email account's inbox disables downloading of 1st email account's inbox messages. No warning of this is given - it just happens behind the scenes. Is this all a conscious design decision (and, if so, why?)? Or is it simply a bug? Is there a solution / workaround? Regards, Bazzaman Just to be clear, selecting or not selecting "Include this server when getting new mail" option has no impact on this one way or the other - it is the attempted sharing of the inbox that gives rise to the issue.