Comment 39 for bug 1748895

6.3.0.4 includes most of the changes I suggested, but still fails to operate properly - it switches the focus to the email client, but fails to create a new email.

I thnk the problem may be at senddoc line 293,
MAILTO="${MAILTO:-}${MAILTO:+&}attach="$(echo "file://$2" | "${URI_ENCODE}")

My email client (Claws-mail) fails to handle the "file://" syntax, as do some other email clients.

My suggestion (lines 269-276 of my proposed revision) was to omit the file:// (at least for xdg-email), so that the command then is
MAILTO="${MAILTO:-}${MAILTO:+&}attach="$(echo "$2" | "${URI_ENCODE}")

That then works; though I found it advisable to omit the ampersand in the mail command (can't immediately remember why, sorry!), so that that command became simply
${MAILER} "${MAILTO}"

Version: 6.3.0.4
Build ID: 1:6.3.0-0ubuntu0.18.04.1~lo2
CPU threads: 4; OS: Linux 4.15; UI render: default; VCL: gtk3;
Locale: en-GB (en_GB.UTF-8); UI-Language: en-GB
Calc: threaded