Telnet smtp.mail - must issue STARTTLS command first
On my Mac terminal, I am trying to telnet into my smtp.gmail.com through port 587.
On Google Apps, (which is set to manage a Dreamhost domain), I have relay configured, as follows:
"Allowed senders: Only addresses in my domains"
"Require SMTP Authentication: Yes"
when I HELO <[email protected]>, I get:
250 smtp.gmail.com at your service
then I enter MAIL FROM: <[email protected]>
which returns:
530 5.7.0 Must issue a STARTTLS command first.
what am I doing wrong?
Answer
You're required to start encrypting the connection first. This is done using the STARTTLS command.
You can use the following command instead of telnet:
openssl s_client -starttls smtp -connect smtp.gmail.com:587
It works like the telnet command, but takes care of starting the encryption first.