I've been running through a tutorial at: http://www.cerebellumstrategies.com/amazon-linux-postfix-dovecot/ and everything works through the entire tutorial right up to checking the authentication.
While inside the instance, I can run:
[ec2-user@domU-... ~]$ openssl s_client -starttls smtp -connect localhost:25 CONNECTED(00000003) didn't found starttls in server response, try anyway... 140326462789448:error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol:s23_clnt.c:699: --- no peer certificate available --- No client certificate CA names sent --- SSL handshake has read 238 bytes and written 148 bytes --- New, (NONE), Cipher is (NONE) Secure Renegotiation IS NOT supported Compression: NONE Expansion: NONE --- [ec2-user@domU-12-31-39-05-61-27 ~]$
But from my own laptop:
Drew-Sonnes-MacBook-Pro:~ drew$ openssl s_client -starttls smtp -connect mail.symbiosislaboratories.com:25 connect: Connection refused connect:errno=61
I have port 25 open in my security group (and have for a few weeks). For the purpose of debugging my problem, I have iptables turned off:
[ec2-user@domU-... ~]$ sudo service iptables status iptables: Firewall is not running.
I have requested my reverse DNS and port 25 open from Amazon, and they put that through a couple of days ago. I've made sure my DNS is resolving correctly. I've run through the tutorial, fixed typos, double & triple checked my settings, and can't find anything I've done wrong. Does anyone else know of anything else which would be stopping this?