Install libspf2-2-dbg by entering the following commands in the terminal:
sudo apt update sudo apt install libspf2-2-dbg
Description:
library for validating mail senders with SPF (debugging symbols)
libspf2 implements the Sender Policy Framework, a part of the SPF/SRS protocol pair. . This package contains the debugging symbols.
Homepage: http://www.libspf2.org/
Version: 1.2.10-7build2
Section: universe/debug