I’m a new Thunderbird user. I’m using a Dell PC with Windows 10. Just tried sending a 7mb mp3 file to a recipient via FileLink. I set up a FileLink connection to a Send instance in the USA. Every attempt to send the file to a recipient resulted in endless loading and copying the message to my drafts folder and my sent folder, but the Send button on the message never darkened and allowed me to send the message. Also I get an error message from Thunderbird telling me it can’t copy the message to my drafts and sent folders. After two plus hours of waiting, I had to cancel the messages. Tried restarting Thunderbird.

I tried using Dropbox instead but Dropbox always pauses my uploads no matter what I do and which browser I use. I ended up sending the mp3 file as a regular attachment. That eventually worked but again the message couldn’t be saved to my sent folder, and again Thunderbird insisted on saving a draft copy while the very long file attachment loading process went on for over a half hour. My question is: why does it take so long for Thunderbird to load an attachment to a message, and why doesn’t FileLink work? I tried to send a 1.6mb photo in jpg format to myself, and even that took a half hour, and I wasn’t sure the process worked until I received my message with the photo. Do I need to disable my Norton software to use Thunderbird? Disable my browser extensions? Or do I just need to find a different email client?