"django" error sends email and memcached error

I have an error in the seahub.log file that appears when sending an email from the seafile server:

2018-09-09 10:41:27,207 [ERROR] seahub.auth.views:308 password_reset No module named django_smtp_ssl

mails are not sent …

and I have another error about memcached:

Warning: Cache is not working, please check memcached is running if you are using
memcached backend, otherwise, please check permission of cache directory on your
file system.

the memcached service is started …

root@seafile:~# ps wuax | grep memcache
memcache   351  0.0  0.0 335692   364 ?        Ssl  01:35   0:15 /usr/bin/memcached -m 128 -p 11211 -u memcache -l
root     15320  0.0  0.0  12784   928 pts/0    S+   10:49   0:00 grep memcache

root@seafile:~# service memcached status
● memcached.service - memcached daemon
   Loaded: loaded (/lib/systemd/system/memcached.service; enabled; vendor preset: enabled)
   Active: active (running) since Sun 2018-09-09 01:35:13 CEST; 9h ago
     Docs: man:memcached(1)
 Main PID: 351 (memcached)
    Tasks: 7 (limit: 4915)
   CGroup: /system.slice/memcached.service
           └─351 /usr/bin/memcached -m 128 -p 11211 -u memcache -l

sept. 09 01:35:13 seafile systemd[1]: Started memcached daemon.

Thanks for your help

I solved the problem of emails using this solution which was in the Seafile manual:

I still have to solve the Memcached problem …