I tried to install the plug-in version 1.1.14 and I get this type of error
[ERROR]
Plugin::Mailgraph::_createMailgraphPicture: Could not save png to
'/var/www/imscp/gui/plugins/Mailgraph/tmp_graph/mailgraph_day.png'
ls -asl /var/www/imscp/gui/plugins/Mailgraph/
totale 44
4 drwxr-x--- 4 vu2000 vu2000 4096 set 15 10:27 .
4 drwxr-x--- 13 vu2000 vu2000 4096 set 15 10:28 ..
4 drwxr-x--- 2 vu2000 vu2000 4096 set 15 10:27 backend
4 -rw-r--r-- 1 vu2000 vu2000 1520 set 15 10:27 CHANGELOG
4 -rw-r--r-- 1 vu2000 vu2000 1406 set 15 10:27 config.php
4 -rw-r--r-- 1 vu2000 vu2000 1838 set 20 10:08 cronjob.pl
4 drwxr-x--- 2 vu2000 vu2000 4096 set 15 10:27 frontend
4 -rw-r--r-- 1 vu2000 vu2000 1425 set 15 10:27 info.php
8 -rw-r--r-- 1 vu2000 vu2000 4109 set 15 10:27 Mailgraph.php
4 -rw-r--r-- 1 vu2000 vu2000 1680 set 15 10:27 README.md