Postfix relay sender mail: utente§dominio.it

[Cheis]

Salve a tutti.
Ho realizzato un server mail postfix su debian Lenny che si appoggia  
ad un relay esterno. Le mail vengono spedite correttamente.
Non riesco a capire perchè le mail mi arrivano con un mittente nella  
forma:

> utente§domionio.it



L'invio sui log appare giusto:

> 6AF84788058: from=<utente@dominio.it>, size=706, nrcpt=1 (queue  
> active)...
> Jun  6 16:13:57 WebServer postfix/smtp[3836]: 6AF84788058: to=<xxx@gmail.com 
> >, relay=miail.esterno.it[]:25, delay=1, delays=0.06/0.01/0.49/0.47,  
> dsn=2.6.0, status=sent (250 2.6.0 704 bytes received in 00:00:00;  
> Message id NUV62504 accepted for delivery)
> Jun  6 16:13:57 WebServer postfix/qmgr[3827]: 6AF84788058: removed


Ho creato anche il file sender_canonical in modo che associasse:

> utente§dominio.it utente@dominio.it


Ma non pare che la cosa funzioni.

Dove posso sbagliare???

Il mio file di configurazione è:

> WebServer:/etc/postfix# postconf -n
> alias_database = hash:/etc/aliases
> alias_maps = hash:/etc/aliases
> allow_percent_hack = yes
> append_dot_mydomain = no
> config_directory = /etc/postfix
> disable_dns_lookups = no
> inet_interfaces = all
> mailbox_size_limit = 0
> masquerade_classes = envelope_sender, header_sender, header_recipient
> masquerade_domains = dominio.it
> mydestination = WebServer.dominio.bl, localhost.dominio.bl, localhost
> myhostname = WebServer.dominio.bl
> mynetworks = 127.0.0.0/8, 192.168.0.0/16
> myorigin = /etc/mailname
> readme_directory = no
> relayhost = [mail.esterno.it]
> sender_canonical_maps = hash:/etc/postfix/sender_canonical
> smtp_sasl_auth_enable = yes
> smtp_sasl_password_maps = hash:/etc/postfix/sasl/sasl_passwd
> smtp_sasl_security_options =
> smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
> smtpd_client_restrictions =  
> permit_mynetworks,                            check_client_access  
> hash:/etc/postfix/helo_client_exceptions,                             
> permitsmtpd_helo_required = yes
> smtpd_helo_required = no
> smtpd_helo_restrictions =  
> permit_mynetworks,                          check_client_access  
> hash:/etc/postfix/helo_client_exceptions,                           
> reject_unknown_client,                           
> reject_invalid_hostname,                           
> reject_unauth_pipelining,                           
> reject_unknown_hostname,                           
> reject_non_fqdn_hostname,
> smtpd_recipient_restrictions =  
> permit_mynetworks,                               check_client_access  
> hash:/etc/postfix/ 
> helo_client_exceptions,                                
> reject_unauth_destination
> smtpd_sender_restrictions =  
> permit_mynetworks,                            check_client_access  
> hash:/etc/postfix/helo_client_exceptions,                             
> reject_non_fqdn_sender,                             
> reject_unauth_pipelining,                             
> reject_unknown_sender_domain
> smtpd_tls_cert_file = /etc/ssl/certs/ssl-cert-snakeoil.pem
> smtpd_tls_key_file = /etc/ssl/private/ssl-cert-snakeoil.key
> smtpd_tls_session_cache_database = btree:${data_directory}/ 
> smtpd_scache
> smtpd_use_tls = yes
> strict_rfc821_envelopes = no

Grazie mille. Marco