[CentOS] setting up postfix

[m.roth at 5-cent.us]

Larry Martell wrote:
> On Tue, Oct 16, 2012 at 9:03 AM, Craig White <craig.white at ttiltd.com>
> wrote:
>> On Oct 16, 2012, at 7:02 AM, Larry Martell wrote:
>>
>>> This should be an easy one. I'm trying to get postfix going. I've
>>> never done this before. I followed the directions at
>>> http://wiki.centos.org/HowTos/postfix. I opened port 25:
>>>
>>> iptables -I INPUT -p tcp -m tcp --dport 25 -j ACCEPT
>>>
>>> Here's an attempt to send mail:
<snip>

>>> But I don't receive the mail. In a file in /var/spool/postfix/defer I
>>> see:
>>>
>>> <larry.martell at gmail.com>: connect to
>>> alt2.gmail-smtp-in.l.google.com[2607:f8b0:400d:c00::1a]:25: Network is
>>> unreachable
>>> recipient=larry.martell at gmail.com
>>> offset=654
>>> dsn_orig_rcpt=rfc822;larry.martell at gmail.com
>>> status=4.4.1
>>> action=delayed
>>> reason=connect to
>>> alt2.gmail-smtp-in.l.google.com[2607:f8b0:400d:c00::1a]:25: Network is
>>> unreachable
>>>
>>> Have I missed a step or done something wrong?
>>
>> ----
>> most home broadband providers block outbound port 25 from reaching any
>> smtp servers other than the ones that they provide and typically require
>> authentication in order to stop spam.
>
> This is not a home machine. It's my client's machine on a corporate
> network.

Have you checked with the admins who administer the corporate email and
firewalls? They may have it blocked.

      mark