How to get a “right click, send by email” menu in Nemo file browser:

Create the file:

.local/share/nemo/actions/thunderbird.nemo_action

Just cut and paste this inside that file and you’re done 🙂

[Nemo Action]
Name=Send by Email
Comment=Send by Email the files
Exec=thunderbird -compose to=,"attachment='%U'"
Icon-Name=thunderbird
Selection=notnone
Extensions=nodirs;
Separator=,
EscapeSpaces=false

Source: http://www.badpenguin.org/nemo-action-send-to-email