Whenever I send an email, it sends fine to my mail server and saves a copy perfectly to my "Sent folder". But, Thunderbird hangs forever when trying to save the reply to the "original message" folder. Sometimes, it processes and saves correctly (after a good 15-30+ mins). Other times (after a long period), I have to manually quit the save message and retry. When I do quit and retry a couple of times, it sometimes saves correctly. But, this a hassle to baby-sit the process. I have multiple clients in separate email folders on my mail server. I like to keep all the conversations separate and in a threaded list. I also use multiple computers\devices, so I want the messages always available to me wherever I am. I have "place replies in the folder of the message being replied to" option checked on the "copies and folders" screen. When I have this option unchecked, there isn't any hanging, but then the reply is only in my "Sent" folder. This is fine for items you are replying to in the inbox, but sometimes I am replying to a message that is already in a separate folder on the server. Using Thunderbird 60.4.0 on Mac Any help would be appreciated. Thx.