No supported authentification method when sending email
<p>I tried to send an email using SMTP server but I couldn't. 
I am getting this message: </p>

<pre><code>SMTP-AUTH: No mutually supported authentication methods available
Authentification Failed
</code></pre>

<p>So I connected to server using telnet.</p>

<pre><code>telnet server 2526
ehlo server
250-server Hello [xxx.xxx.xxx.xxx]
250-SIZE 36700160
250-PIPELINING
250-DSN
250-ENHANCEDSTATUSCODES
250-AUTH
250-8BITMIME
250-BINARYMIME
250 CHUNKING
</code></pre>

<p>I think that the server is not configured well, because there isn't STARTTLS option (it's Microsoft Exchange server). I'm a bit confused, because there's AUTH optionm but I don't know what does it mean. Thank you for any help.</p>