On Wed, 11 Jan 2017, David Wood wrote:

>> STARTTLS
> < 454 TLS not available due to temporary reason
>
> And the curl session then hangs. After 15-20 minutes, curl finally responds
> with:
> * Recv failure: Connection timed out
> * Send failure: Broken pipe
> * Closing connection 52
>
> Is there something different I have to do to release/terminate the connection
> as soon as I get the 454 response?

No... It is supposed to immediately see that it isn't a 220 and then move on
to do authentication:

  https://github.com/curl/curl/blob/master/lib/smtp.c#L693

There's nothing extra going on for the response reading after a STARTTLS so if
you hadn't said it happened on multiple servers I would've suspected something
on the server side. :-/

-- 
  / daniel.haxx.se
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