Sent Items folders not syncing on Thunderbird

Sent Items folders not syncing on Thunderbird

HI, 
I run TB on multiple devices, since the middle of September all the devices have stopped synchronising the sent items folders, all mail is received and sent correctly and stored in my zoho webfolders. I haven't changed any of the settings.
Any ideas?
This is also the case in my 'paid for' accounts with ZOHO and Thunderbird
Many thanks
Tony whittingham




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