Sometimes it is nice to send a log or some other file as a email to someone (or a part of a file)
cat myfile.txt | mail -s 'SUBJECT' email@example.com;
Change myfile.txt, SUBJECT and firstname.lastname@example.org to something useful.
It is also possible to send the output of a command to someone
ps -ef|mail -s 'SUBJET' email@example.com;