how to send email from an instance without using sendgrid? [closed]

Question

My project up and beta running on google compute engine. I want to set-up email server. For that i followed http://www.krizna.com/centos/setup-mail-server-in-centos-6/

I edited /etc/postfix/main.cf exactley how they mentioned and here is few more details

myhostname = mx.audiworld.com
mydomain = audiworld.com
mynetworks = <compute-instance-ip>,127.0.0.1/8

when I issue telnet localhost 25 I am getting below error

[root@myinstance-1 ~]# telnet localhost 25
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused

but namp localhost gives me

Starting Nmap 6.40 ( http://nmap.org ) at 2014-11-06 09:48 UTC
Nmap scan report for localhost (127.0.0.1)
Host is up (0.000011s latency).
Other addresses for localhost (not scanned): 127.0.0.1
Not shown: 992 closed ports
PORT    STATE SERVICE
21/tcp  open  ftp
22/tcp  open  ssh
80/tcp  open  http
110/tcp open  pop3
143/tcp open  imap
465/tcp open  smtps
993/tcp open  imaps
995/tcp open  pop3s

Nmap done: 1 IP address (1 host up) scanned in 2.42 seconds

so the smtp port is 465 right ? then telnet localhost 465 finally got it working

Ok this what google is telling

Google Compute Engine does not allow outbound connections on ports 25, 465, and 587 but you can still set up your instances to send mail through ports 587 and 465 using servers provided through partner services, such as SendGrid. This document discusses how to set up your instances to send email using SendGrid.

but I don't want sendgrid to manage email . without using sendgrid how to setup Email server.?

Answer 1

You can't. The text is clear: Google Compute Engine does not allow outbound connections on ports 25, 465, and 587.

If that doesn't work for you, you are on the wrong platform.