This is a fairly good explanation on the error http://www.massmailsoftware.com/smtp/554-5-7-1.php
> On 2 Jun 2015, at 16:44, Noel <noeld...@gmail.com> wrote: > > Yes, dovecot handles the authentication, but the connection is > handled by postfix. We already know the authentication work since > you can receive mail, so the problem is either postfix or the client. > At any rate, this isn't a dovecot problem. > > > > -- Noel Jones > > > > On 6/2/2015 12:38 AM, SH Development wrote: >> Correct me if I’m wrong, but I thought Dovecot handled client >> authentication, and once authenticated handed off to postfix? >> >> >>> On Jun 1, 2015, at 10:05 PM, Noel <noeld...@gmail.com> wrote: >>> >>> On 6/1/2015 6:27 PM, SH Development wrote: >>>> Dovecot 2.0.9 >>>> >>>> I am able to connect successfully with Thunderbird, Win 8, Apple Mail, >>>> iPhone, iPad. >>>> >>>> Outlook Express on Win XP receives just fine, but will not send. I get a >>>> "Client host rejected: Access denied” message. I believe this is simply >>>> Postfix telling me the connection isn’t properly authenticated, as setting >>>> up the exact same credentials on another client (non OE) works. It is >>>> only with OE on XP that I am unable to send/authenticate. >>>> >>>> I have literally tried every combination of settings in OE and nothing >>>> works. What else might I need to enable to get this working? >>>> >>>> Using SSL, ports 993, 587 PLAINTEXT. >>> Sounds like a problem with postfix talking to your XP client, not a >>> dovecot problem. >>> >>> If you've changed the tls settings in postfix recently, you likely >>> broke compatibility with older clients. If you need further help, >>> feel free to ask on the postfix-users list. Be sure to include >>> "postconf -nf" and "postconf -Mf" output, along with related log >>> entries demonstrating the problem. >>> http://www.postfix.org/DEBUG_README.html#mail >>> >>> >>> -- Noel Jones >>> >>> >>> >>> >>>> dovecot -n as follows: >>>> >>>> # 2.0.9: /etc/dovecot/dovecot.conf >>>> # OS: Linux 2.6.32-504.16.2.el6.x86_64 x86_64 CentOS release 6.6 (Final) >>>> ext4 >>>> log_timestamp = "%Y-%m-%d %H:%M:%S " >>>> mail_location = maildir:/home/vmail/%d/%n/Maildir >>>> mail_max_userip_connections = 50 >>>> namespace { >>>> inbox = yes >>>> location = >>>> prefix = INBOX. >>>> separator = . >>>> type = private >>>> } >>>> passdb { >>>> args = /etc/dovecot/dovecot-sql.conf >>>> driver = sql >>>> } >>>> protocols = imap pop3 >>>> service auth { >>>> unix_listener /var/spool/postfix/private/auth { >>>> group = postfix >>>> mode = 0660 >>>> user = postfix >>>> } >>>> unix_listener auth-master { >>>> mode = 0600 >>>> user = vmail >>>> } >>>> user = root >>>> } >>>> ssl_ca = </etc/pki/dovecot/certs/intermediate.pem >>>> ssl_cert = </etc/pki/dovecot/certs/dovecot.pem >>>> ssl_key = </etc/pki/dovecot/private/dovecot.pem >>>> userdb { >>>> args = uid=5000 gid=5000 home=/home/vmail/%d/%n allow_all_users=yes >>>> driver = static >>>> } >>>> protocol lda { >>>> auth_socket_path = /var/run/dovecot/auth-master >>>> log_path = /home/vmail/dovecot-deliver.log >>>> postmaster_address = postmas...@starionhost.net >>>> } >>>> protocol pop3 { >>>> pop3_uidl_format = %08Xu%08Xv >>>> }
