Error opening device, you don't have permissions (after gammu install)

Just after installing the gammu and configuring the .gammrc in my home directory (/home/rafael/.gammurc), I get this error and I do not know what file I have to give "sufficient permissions.

gammu sendsms TEXT 04165181317 -text "Hallooo.."

Error opening device, you don't have permissions

This is my configuration file:

rafael@Aspire-one-Lubuntu16:~$ cat .gammurc
[gammu]
port = /dev/ttyUSB0
connection = at    

[gammu1]
port = /dev/ttyUSB1
connection = at

[gammu2]
port = /dev/ttyUSB2
connection = at

The ttyUSB* belongs to group "dialout"

rafael@Aspire-one-Lubuntu16:~$ ls -l /dev/ttyUSB*
crw-rw---- 1 root dialout 188, 0 ago  8 20:00 /dev/ttyUSB0
crw-rw---- 1 root dialout 188, 1 ago  8 18:52 /dev/ttyUSB1
crw-rw---- 1 root dialout 188, 2 ago  8 19:19 /dev/ttyUSB2

And add my user "rafael to this group:

usermod -a -G dialout rafael

Any idea to help me??? thanks!!

Solution

You have to give goods permissions to gammu:

chown root:gammu /usr/bin/gammu
usermod -a -G gammu rafael