Sending mail by unattended upgrade

Some people had met some similar problems but nothing solves my problem; my log file # tail -f /var/log/unattended-upgrades/unattended-upgrades.log 2018-02-18 13:25:37,656 DEBUG No conffiles in deb '/var/cache/apt/archives/libgfortran3_4.9.2-10+deb8u1_amd64.deb' (There is no member named 'conffiles') 2018-02-18 13:25:37,657 DEBUG blacklist: [] 2018-02-18 13:25:37,658 DEBUG whitelist: [] 2018-02-18 13:25:37,658 DEBUG InstCount=23 DelCount=0 BrokenCount=0 2018-02-18 13:25:37,660 INFO Packages that will be upgraded: cpp-4.9 g++-4.9 gcc-4.9 gcc-4.9-base gcc-4.9-base:i386 libasan1 libatomic1 libcilkrts5 libgcc-4.9-dev libgcc1 libgcc1:i386 libgfortran3 libgomp1 libitm1 liblsan0 libobjc-4.9-dev libobjc4 libquadmath0 libstdc++-4.9-dev libstdc++6 libstdc++6:i386 libtsan0 libubsan0 2018-02-18 13:25:37,662 INFO Writing dpkg log to '/var/log/unattended- upgrades/unattended-upgrades-dpkg.log' 2018-02-18 13:27:02,483 INFO All upgrades installed 2018-02-18 13:27:02,485 DEBUG Extracting content from '/var/log/unattended-upgrades/unattended-upgrades-dpkg.log' since '2018- 02-18 13:25:37.661632' 2018-02-18 13:27:02,511 DEBUG Sending mail to 'xxxyyyy@gmail.com' 2018-02-18 13:27:02,713 DEBUG mail returned: 0 # cat /etc/apt/listchanges.conf [apt] frontend=pager email_address=xxxyyyy@gmail.com confirm=0 save_seen=/var/lib/apt/listchanges.db which=news But the message doesn't go to my email address. Of course mailx makes the job: $ echo "Just testing mailx" | mail -s "Yooo woot" xxxyyyy@gmail.com and I receive my message... I'm using smtp configuration in my .mailrc file So what can I do? thanks for your helps