~/.reportbugrc

# reportbug preferences file
# character encoding: UTF-8
# Version of reportbug this preferences file was written by
reportbug_version "6.6.3"
# default operating mode: one of: novice, standard, advanced, expert
mode novice
# default user interface
ui gtk2
# offline setting - comment out to be online
#offline
# name and email setting (if non-default)
# realname "Jan Kowalski"
email "user-reportbug@server.org"
# Send all outgoing mail via the following host
smtphost "smtp.server.org"
smtpuser "user"
#smtppasswd "my password here"
# Enable TLS for the SMTP host
smtptls
# If nothing else works, remove the # at the beginning
# of the following three lines:
#no-cc
#header "X-Debbugs-CC: user-reportbug@server.org"
#smtphost reportbug.debian.org
# You can add other settings after this line.  See
# /etc/reportbug.conf for a full listing of options.

To send saved report (can be found in /tmp directory):

sudo sendmail -t < reportbug-openvpn-20200313-388598-1lq5adpb