I have my personal email hosted on OVH (personal hosting plan) and I'm not able to send mails using msmtp.

Here's a typical session

ignoring system configuration file /etc/msmtprc: File o directory non esistente
loaded user configuration file /home/klez/.msmtprc
using account default from /home/klez/.msmtprc
host                  = ssl0.ovh.net
port                  = 465
timeout               = off
protocol              = smtp
domain                = localhost
auth                  = choose
user                  = federicoculloca%xxxxxxx
password              = *
ntlmdomain            = (not set)
tls                   = on
tls_starttls          = off
tls_trust_file        = (not set)
tls_crl_file          = (not set)
tls_fingerprint       = (not set)
tls_key_file          = (not set)
tls_cert_file         = (not set)
tls_certcheck         = off
tls_force_sslv3       = off
tls_min_dh_prime_bits = (not set)
tls_priorities        = (not set)
auto_from             = off
maildomain            = (not set)
from                  = federicoculloca@xxxxxxxx
dsn_notify            = (not set)
dsn_return            = (not set)
keepbcc               = off
logfile               = (not set)
syslog                = (not set)
reading recipients from the command line
TLS certificate information:
    Owner:
        Common Name: ssl0.ovh.net
        Organizational unit: Domain Control Validated
    Issuer:
        Common Name: OVH Secure Certification Authority
        Organization: OVH SAS
        Organizational unit: Low Assurance
        Country: FR
    Validity:
        Activation time: lun 31 gen 2011 01:00:00 CET
        Expiration time: mer 15 feb 2012 00:59:59 CET
    Fingerprints:
        SHA1: F9:DC:41:F9:A2:38:51:9B:56:E4:98:E6:CD:81:31:42:E6:0E:26:6D
        MD5:  FC:EC:F3:8F:28:E4:7E:28:99:89:E6:BB:C9:DF:71:CE
<-- 220 ns0.ovh.net ssl0.ovh.net. You connect to mail427.ha.ovh.net ESMTP

--> EHLO localhost

<-- 250-ssl0.ovh.net. You connect to mail427.ha.ovh.net

<-- 250-AUTH LOGIN PLAIN

<-- 250-AUTH=LOGIN PLAIN

<-- 250-PIPELINING

<-- 250-8BITMIME

<-- 250 SIZE 109000000

--> AUTH PLAIN xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

<-- 235 ok, go ahead (#2.0.0)

--> MAIL FROM:<federicoculloca@xxxxx>

--> RCPT TO:<[email protected]>

--> DATA

<-- 250 ok

<-- 250 ok

<-- 354 go ahead

--> hello world

--> .

<-- 554 mail server permanently rejected message (#5.3.0)

And my configuration

# ~/.msmtp
# Mostly from Peter Garrett's examples
#  https://lists.ubuntu.com/archives/ubuntu-users/2007-September/122698.html
# Accounts from Scott Robbins' `A Quick Guide to Mutt'
#  http://home.nyc.rr.com/computertaijutsu/mutt.html

account xxxxx
host ssl0.ovh.net
from federicoculloca@xxxxxx
auth on
user federicoculloca%xxxxxx
password xxxxxx
tls on
tls_certcheck off
tls_starttls off

Any idea?