# postfix connection timed out issue on centOS

**URL:** <https://community.unix.com/t/postfix-connection-timed-out-issue-on-centos/252553>\
**Category:** Red Hat\
**Created:** [October 31, 2009, 8:05am UTC](https://community.unix.com/t/postfix-connection-timed-out-issue-on-centos/252553 "2009-10-31T08:05:12Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![oracle.test2](https://community.unix.com/letter_avatar/oracle.test2/32/5_5575768a8748004e209b776fc1b2916d.png) [@oracle.test2](https://community.unix.com/u/oracle.test2)\
**Post date:** [October 31, 2009, 8:05am UTC](https://community.unix.com/t/postfix-connection-timed-out-issue-on-centos/252553/1 "2009-10-31T08:05:12Z")

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hello everyone

i hav LITTLE issue, pending for just last week regarding postfix/sendmail server.  
M not able to forward mail to outer domain.  
I hav not configured DNS server uptill now, so nvr tried to receive mail from any domain, as i don require that as of now.  
Can anybody suggest a lifeline for that, coz i don want to b a millionaire, just want to resolve this issue.

error: connect to [c.mx.mail.yahoo.com](http://c.mx.mail.yahoo.com)[216.39.53.3]: Connection timed out

Mentionable: OS:- centOS 5.3  
Postfix able to sendmail in inner domain  
SELinux is disabled.  
Port used to communicate is 25  
Please tell the pattern if , if any, in detail, as i am new to linux.

thanks....

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<div class="post-metadata">

**Author:** ![fpmurphy](https://community.unix.com/user_avatar/community.unix.com/fpmurphy/32/110_2.png) [@fpmurphy](https://community.unix.com/u/fpmurphy)\
**Post date:** [October 31, 2009, 9:30am UTC](https://community.unix.com/t/postfix-connection-timed-out-issue-on-centos/252553/2 "2009-10-31T09:30:37Z")

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I am confused. Are you trying to use both Postfix and sendmail? You can use only one or the other but not both at the same time.

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<div class="post-metadata">

**Author:** ![oracle.test2](https://community.unix.com/letter_avatar/oracle.test2/32/5_5575768a8748004e209b776fc1b2916d.png) [@oracle.test2](https://community.unix.com/u/oracle.test2)\
**Post date:** [November 1, 2009, 11:59pm UTC](https://community.unix.com/t/postfix-connection-timed-out-issue-on-centos/252553/3 "2009-11-01T23:59:31Z")

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hello Murphy

Well the thing is, i hav tried installing both of them, not simultaneously, but failed with both to send mail to outer domain and having almost same issue...

Previously , i was trying with sendmail, then somewhre i read that sendmail is not a gud option for centOS, so i switched to postfix,and not able to get the required output with postfix as well and the error: connection timed out..

thanks

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<div class="post-metadata">

**Author:** ![oracle.test2](https://community.unix.com/letter_avatar/oracle.test2/32/5_5575768a8748004e209b776fc1b2916d.png) [@oracle.test2](https://community.unix.com/u/oracle.test2)\
**Post date:** [November 3, 2009, 11:47pm UTC](https://community.unix.com/t/postfix-connection-timed-out-issue-on-centos/252553/4 "2009-11-03T23:47:43Z")

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I am not getting any response too, by telnet the ip address of the receiver domain.

Whats cud be the issue...

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<div class="post-metadata">

**Author:** ![fpmurphy](https://community.unix.com/user_avatar/community.unix.com/fpmurphy/32/110_2.png) [@fpmurphy](https://community.unix.com/u/fpmurphy)\
**Post date:** [November 4, 2009, 9:11am UTC](https://community.unix.com/t/postfix-connection-timed-out-issue-on-centos/252553/5 "2009-11-04T09:11:24Z")

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Postfix, by default, will forward mail to authorized remote destinations only. Authorized remote destinations are defined with the relay\_domains configuration parameter. The default is to authorize all domains (and subdomains) of the domains listed with the mydestination parameter.

Example:

```nohighlight
        relay_domains = $mydestination

```

What is your $mydestination set to?

Postfix, by default, attempts to deliver mail directly to the Internet. However your system may be behind a firewall, or it may be connected via a provider who does not allow direct mail to the Internet. In those cases you need to configure Postfix to deliver mail indirectly via a relay host. You should specify one (and only one) of the following:

```nohighlight
        relayhost = (default: direct delivery to Internet)
        relayhost = $mydomain (deliver via local mailhub)
        relayhost = [mail.$mydomain] (deliver via local mailhub)
        relayhost = [mail.isp.tld] (deliver via provider mailhub)

```