Below is a rough list of functions disabled and enabled on our free hosting services, many were only disabled after abuse was found to be an issue and we are constantly working on relaxing and/or enabling disabled functionality.

These functions are however fully supported on our premium plan.

E-mail Related
SMTP Support: DISABLED
IMAP Support: DISABLED

.htaccess Related
Some directives and functions are not enabled/supported at this point in time due to past abuse.

PHP Specific
PHP Sendmail: DISABLED
PHP Safemode: OFF

fopen wrappers/curl: DISABLED

The following is a list of disabled functions in PHP:

exec
system
passthru
shell_exec
escapeshellarg
escapeshellcmd
proc_close
proc_open
ini_alter
dl
popen
show_source
curl_exec
popen
pcntl_exec
socket_accept
socket_bind
socket_clear_error
socket_close
socket_connect
socket_create_listen
socket_create_pair
socket_create
socket_get_option
socket_getpeername
socket_getsockname
socket_last_error
socket_listen
socket_read
socket_recv
socket_recvfrom
socket_select
socket_send
socket_sendto
socket_set_block
socket_set_nonblock
socket_set_option
socket_shutdown
socket_strerror
socket_write
stream_socket_client
stream_socket_server
pfsockopen
stream_set_timeout
ftp_alloc
ftp_cdup
ftp_chdir
ftp_chmod
ftp_close
ftp_connect
ftp_delete
ftp_exec
ftp_fget
ftp_fput
ftp_get_option
ftp_get
ftp_login
ftp_mdtm
ftp_mkdir
ftp_nb_continue
ftp_nb_fget
ftp_nb_fput
ftp_nb_get
ftp_nb_put
ftp_nlist
ftp_pasv
ftp_put
ftp_pwd
ftp_quit
ftp_raw
ftp_rawlist
ftp_rename
ftp_rmdir
ftp_set_option
ftp_site
ftp_size
ftp_ssl_connect
ftp_systype
chown
getrusage
get_current_user
set_time_limit
getmyuid
getmypid
dl
leak
listen
chgrp
link
symlink
globexec
system
passthru
shell_exec
escapeshellarg
escapeshellcmd
proc_close
proc_open
ini_alter
dl
popen
show_source
curl_exec
popen
pcntl_exec
socket_accept
socket_bind
socket_clear_error
socket_close
socket_connect
socket_create_listen
socket_create_pair
socket_create
socket_get_option
socket_getpeername
socket_getsockname
socket_last_error
socket_listen
socket_read
socket_recv
socket_recvfrom
socket_select
socket_send
socket_sendto
socket_set_block
socket_set_nonblock
socket_set_option
socket_shutdown
socket_strerror
socket_write
stream_socket_client
stream_socket_server
pfsockopen
stream_set_timeout
ftp_alloc
ftp_cdup
ftp_chdir
ftp_chmod
ftp_close
ftp_connect
ftp_delete
ftp_exec
ftp_fget
ftp_fput
ftp_get_option
ftp_get
ftp_login
ftp_mdtm
ftp_mkdir
ftp_nb_continue
ftp_nb_fget
ftp_nb_fput
ftp_nb_get
ftp_nb_put
ftp_nlist
ftp_pasv
ftp_put
ftp_pwd
ftp_quit
ftp_raw
ftp_rawlist
ftp_rename
ftp_rmdir
ftp_set_option
ftp_site
ftp_size
ftp_ssl_connect
ftp_systype
chown
getrusage
get_current_user
set_time_limit
getmyuid
getmypid
dl
leak
listen
chgrp
link
symlink
glob