mail not sending or receiving ?

I configured a mail server on ubuntu 14.04 using postfix and dovecot. When I'm trying to send mail or receive mail then it's not working and GENERATING no error.

mail log

Jun 11 07:40:18 mail postfix/qmgr[1105]: CF1EC123BD7: from=<>, size=732, nrcpt=1 (queue active)
Jun 11 07:40:18 mail postfix/qmgr[1105]: E8A591239D7: from=<>, size=3593, nrcpt=1 (queue active)
Jun 11 07:40:18 mail postfix/smtp[6963]: connect to gmail-smtp-in.l.google.com[2607:f8b0:400d:c04::1b]:25: Network is unreachable
Jun 11 07:40:48 mail postfix/smtp[6962]: connect to gmail-smtp-in.l.google.com[74.125.29.26]:25: Connection timed out
Jun 11 07:40:48 mail postfix/smtp[6962]: connect to gmail-smtp-in.l.google.com[2607:f8b0:400d:c04::1b]:25: Network is unreachable
Jun 11 07:40:48 mail postfix/smtp[6962]: connect to alt1.gmail-smtp-in.l.google.com[2800:3f0:4003:c01::1a]:25: Network is unreachable
Jun 11 07:40:48 mail postfix/smtp[6963]: connect to gmail-smtp-in.l.google.com[74.125.29.26]:25: Connection timed out
Jun 11 07:41:18 mail postfix/smtp[6962]: connect to alt1.gmail-smtp-in.l.google.com[64.233.190.26]:25: Connection timed out
Jun 11 07:41:18 mail postfix/smtp[6962]: connect to alt2.gmail-smtp-in.l.google.com[2a00:1450:400b:c02::1b]:25: Network is unreachable
Jun 11 07:41:18 mail postfix/smtp[6963]: connect to alt1.gmail-smtp-in.l.google.com[64.233.190.26]:25: Connection timed out
Jun 11 07:41:18 mail postfix/smtp[6963]: connect to alt1.gmail-smtp-in.l.google.com[2800:3f0:4003:c01::1b]:25: Network is unreachable
Jun 11 07:41:18 mail postfix/smtp[6963]: connect to alt2.gmail-smtp-in.l.google.com[2a00:1450:400b:c02::1b]:25: Network is unreachable
Jun 11 07:41:18 mail postfix/smtp[6962]: CF1EC123BD7: to=<>, relay=none, delay=18386, delays=18326/0.02/60/0, dsn=4.4.1, status=deferred (connect to alt2.gmail-smtp-in.l.google.com[2a00:1450:400b:c02::1b]:25: Network is unreachable)
Jun 11 07:41:18 mail postfix/smtp[6963]: E8A591239D7: to=<>, relay=none, delay=19458, delays=19398/0.02/60/0, dsn=4.4.1, status=deferred (connect to alt2.gmail-smtp-in.l.google.com[2a00:1450:400b:c02::1b]:25: Network is unreachable)

It's showing Network is unreachable

I'm a beginner. If any one tell me to then it'll help me to go forward.

thank's in advance.

2 Answers

The problem could be that Postfix is trying to use ipv6. If this the case then the solution would be disabling ipv6 in /etc/postfix/main.cf by commenting the line

# inet_protocols = all

and adding line

inet_protocols = ipv4

Then restarting Postfix service

service postfix restart

If you have a dynamic IP address, your ISP may be blocking traffic on port 25. You have two options:

• Use the ISPs relay to send your mail. This should be the smarthost option when you configure postfix.
• Configure postfix to use the submission port with the required credentials to logon to your gmail account.

If you have configured a firewall, you need to enable outgoing traffic on port 25 to sent email.

If you have a static IP address, you need to get your ISP to set the correct pointer record. You may need to get them to unblock port 25 for you as well. You will also need to setup the appropriate DNS records. This should include A, MX and SPF records as well as possibly DKIM and DMARC records. If you don't already have your own domain, you will need to register one. This will get you started on not having your mail classified as Spam.

The items listed for sending from an static IP address should get you started on receiving email. You may also want to review Running a home email server using dynamic DNS.