OFF Proftpd

Pessoal boa tarde, instalei o proftpd e de dentro da minha rede acesso sem problemas, meu problema está externamente, fiz a regra que libera no firewall, mais mesmo assim ao tentar a conexão recebo uma mensagem que não tenho permissão.

Estou acessando com o usuário ftp, o mesmo está no grupo nogroup e sua pasta está com a permissão 775.

Segue meu conf do proftpd, agradeço se alguém poder ajudar.

#
# /etc/proftpd.conf -- This is a basic ProFTPD configuration file.
# To really apply changes reload proftpd after modifications.
#

ServerName                    "Teste"
ServerType                      standalone
DeferWelcome                off

MultilineRFC2228           on
DefaultServer                   on
ShowSymlinks                 on

TimeoutNoTransfer         600
TimeoutStalled                600
TimeoutIdle                     1200

DisplayLogin                    welcome.msg
DisplayFirstChdir               .message
ListOptions                     "-l"

DenyFilter \*.*/

# Uncomment this if you are using NIS or LDAP to retrieve passwords:
#PersistentPasswd off

# Uncomment this if you would use TLS module:
#TLSEngine on

# Uncomment this if you would use quota module:
#Quotas on

# Uncomment this if you would use ratio module:
#Ratios on

# Port 21 is the standard FTP port.
Port 21

# To prevent DoS attacks, set the maximum number of child processes
# to 30. If you need to allow more than 30 concurrent connections
# at once, simply increase this value. Note that this ONLY works
# in standalone mode, in inetd mode you should use an inetd server
# that allows you to limit maximum number of processes per service
# (such as xinetd)
MaxInstances 30

# Set the user and group that the server normally runs at.
User nobody
Group nogroup

# Umask 022 is a good standard umask to prevent new files and dirs
# (second parm) from being group and world writable.
Umask 022 022

# Normally, we want files to be overwriteable.
AllowOverwrite on

# Delay engine reduces impact of the so-called Timing Attack described in
# http://security.lss.hr/index.php?page=details&ID=LSS-2004-10-02
# It is on by default.
#DelayEngine off

ServerIdent                      off
TimesGMT                      off
WtmpLog                         off
SystemLog                       /var/log/proftpd.log
TransferLog                     /var/log/xferlog
MaxClientsPerHost        4 "Maximo de Clientes Atingido"
MaxLoginAttempts          3
DefaultRoot                     ~
RootLogin                        off
RequireValidShell           off
UseFtpUsers                    off

Não coloquei a parte do anonimo pois não estou utilizando a mesma.