Thank you for your reply.

This is my Xeams log:

2017-09-25 18:00:48,543 INFO  xeams.ServerStarter$1 - Server terminating...
2017-09-25 18:01:01,360 INFO  xeams.ServerStarter - ---------------------------------------------------
2017-09-25 18:01:01,416 INFO  xeams.ServerStarter - Starting server. Current directory = /share/My_NAS/.qpkg/Xeams. Time = 9/25/17 6:01 PM. Build number: 5948 on Linux
2017-09-25 18:01:18,818 INFO  xeams.d - Web server started on port: 5272
2017-09-25 18:01:21,002 INFO  db.b - Database server successfully started.
2017-09-25 18:01:23,218 INFO  xeams.rulesengine - Good folder is: /share/My_NAS/.qpkg/Xeams/GoodEmails
2017-09-25 18:01:23,218 INFO  xeams.rulesengine - Spam folder is: /share/My_NAS/.qpkg/Xeams/SpamEmails
2017-09-25 18:01:23,219 INFO  xeams.rulesengine - Possible spam folder is: /share/My_NAS/.qpkg/Xeams/PossibleSpams
2017-09-25 18:01:33,930 INFO  xeams.ServerStarter - Profile 1 initialized.
2017-09-25 18:01:34,764 INFO  xeams.ServerStarter - Last LCID set to 10647
2017-09-25 18:01:34,801 INFO  users.j - Registering User Repository Ensurer
2017-09-25 18:01:34,927 INFO  connector.d - Smtp proxy server is NOT enabled.
2017-09-25 18:01:35,131 ERROR J.d - Failure starting staging server. Make sure no other program is listening on port 25. java.security.NoSuchAlgorithmException: Error constructing implementation (algorithm: Default, provider: SunJSSE, class: sun.security.ssl.SSLContextImpl$DefaultSSLContext)
2017-09-25 18:01:35,154 ERROR server.n - Failure starting IMAP server. Make sure no other program is listening on port 143 - java.security.NoSuchAlgorithmException: Error constructing implementation (algorithm: Default, provider: SunJSSE, class: sun.security.ssl.SSLContextImpl$DefaultSSLContext)
2017-09-25 18:01:35,167 ERROR r.c - Failure starting Pop3 server. Make sure no other program is listening on port.  java.security.NoSuchAlgorithmException: Error constructing implementation (algorithm: Default, provider: SunJSSE, class: sun.security.ssl.SSLContextImpl$DefaultSSLContext)
2017-09-25 18:01:41,767 INFO  xeams.ServerStarter$6 - IP lookup database initialized in 6961 ms
2017-09-25 18:01:42,486 INFO  xeams.ServerStarter - Initialization completed successfully.

Log says "Make sure no other program is listening on port"

No, since this command :

nmap 192.168.1.0-255 -p 25

did not tell port 25 is listened in my network (without Xeams running). Same thing with ports 110, 143, 465, 993, 995.

Log says "java.security.NoSuchAlgorithmException: Error constructing implementation (algorithm: Default, provider: SunJSSE, class: sun.security.ssl.SSLContextImpl$DefaultSSLContext)"

It probably refers to the SSL configuration. That's why I suspected the self-signed certificate I wanted to use. Should I specify a HTTP port somewhere as you mentionned? Where? (Check for update is working, then Xeams access normaly to your server).

When I try to use ports 465, 993 or 995 the servers say NOT RUNNING. If I put -1 in the SSL ports, the servers say RUNNING.

Thank you for your help.