I sent a message with 2 large attachments, which came to about 700kb. I have my email account configured to move replies to the original message folder after sending. The sent message appears blank in the folder. View source reveals little but starts with the following: ''X-Mozilla-Status: 0001 X-Mozilla-Status2: 00000000 IesvbLYCv+2WRXVrCMCm89IOemygPZpNbz2NBY [and so on for 433 lines of 73 bytes]'', < 32kb. When I use my online webmail interface, the message that Thunderbird can no longer read is intact, legible and contains both the large attachments. The same is true when viewed in another email client. I have restored the message by exporting it from the webmail and importing it back to Thunderbird (to keep my records intact), which Thunderbird handles okay. The outgoing mail server log shows that the message received from Thunderbird and sent to the final recipient was the correct 700kb+ size. I'm rather curious as to what went on there. Attachments to post: 1. View of the corrupt message in the Trash folder 2. Intact message after importing as an export from webmail.