Re: SMTP and TLS

[thewebsi]

HELO adsf
Connection closed by foreign host.

The telnet test certainly does away with any theory that the port might be blocked. It is clearly open, and there is a listener on the other end. However, your scripts go much further than this, actually attempting to negotiate an encrypted connection, log in, and even send a message. The script is likely failing at a later stage.

At this point, I would want to test the server to see if it indeed supports TLS, the authentication information you have is correct, and that you are allowed to use it to send messages. The server might be set up to hang if it's not happy with the transaction (this is a common way to slow down spambots). Unfortunately, this behaviour may mean that you won't get much in the way of useful error messages (as you've already noticed).

I've used this guide before to test SMTP servers for access. It uses command-line tools, but you can certainly use Net::SMTP for example to achieve the same. Note that this is unlikely to be an issue particular to Perl.

[Rodster001]

I did get a response from Amazon:

At the moment, the Amazon SES SMTP interface supports connections wrapped with TLS. This means that the telnet command won't work as a troubleshooting mechanism. With OpenSSL installed, try the following:

openssl s_client -quiet -crlf -connect email-smtp.us-east-1.amazonaws.com:465

After establishing a TLS connection, we will provide the typical SMTP banner.

So, I gave that a shot and:

# openssl s_client -quiet -crlf -connect email-smtp.us-east-1.amazonaws.com:465
depth=2 /C=US/O=VeriSign, Inc./OU=VeriSign Trust Network/OU=(c) 2006 VeriSign, Inc. - For authorized use only/CN=VeriSign Class 3 Public Primary Certification Authority - G5
verify error:num=20:unable to get local issuer certificate
verify return:0
220 email-smtp.amazonaws.com ESMTP SimpleEmailService-200596653
quit
221 Bye


I need to do a little bit of investigation, not sure if that issue is on my end or theirs. I also tried another package (Net::SMTP::TLS). But it too just hangs on connect.

Let me know if you have any ideas, otherwise I will post what I find here.