Send to Mail Recipient in Thunar always gives me this error.
I’m sure I have Googled for a solution this many times before but never found one. Today I did. It’s simply that exo depends on perl-uri to complete this action. It’s even an optdepend in Arch:
Optional Deps : perl-uri: for mail-compose helper script
pacman -S perl-uri
fixes it with no further effort.