Hi Mozilla Community I have attached a large-ish file 19.7 mb (a video) to an email. Pressed send and an alert comes up telling me I should use file share because ... and this is my issue .... the email is (now) 27 mb in size. I have updated Thunderbird, I'm using Imap and the TB version is 91.9.1 My computer is a two year old HP X360 laptop running Win10. I'm also using Bitdefender Total Security. I have tried several times with blank emails (no words) and a video attachment and some with just a few words and the attachment and also with other size attachments. Same result. This also happened with a 33mb pdf attachment, the alert saying the email size is 43mb I don't know where this extra 7mb or 10mb is coming from unless the alert calculation is wrong. Surely sending a blank email doesn't require this much data. I'm interested in others views and ideas. regards David