A probably dumb question, but I'm stumped

[Plutocrat]

On 30/11/2020 04.31, Christy S wrote:
> Your message was sent but a copy was not placed in your sent folder (Sent) due to network or file access errors.

When I've had this error in Thunderbird before it was because I was out of disk space (actually this was a POP account, so it was disk space on my local computer)

So my guess would be check disk space and permissions wherever Thunderbird is trying to write a Sent message. 

P,.