You can attach them, but you're reliant on the recipient having something that can read them. A general answer is that you can copy-and-paste the document contents into an email message in Thunderbird, but you may lose some layout or formatting. And there are several options under '''File|Send''' in LO Writer, but I see they are all about sending your work as an attachment. Note you have to set Thunderbird as the default email client under '''Tools|Options''' in LO.