symfony swift mailer host name
<p>This my <code>parameter.yml</code></p>

<pre><code>parameters:
database_host: localhost
database_port: null
database_name: mongodb
database_user: mongodb
database_password: *******
mailer_transport: smtp
mailer_host: //which host?
mailer_user: support@domain.com
mailer_password: *****
secret: ThisTokenIsNotSoSecretChangeIt
</code></pre>

<p>And this is my <code>config.yml</code></p>

<pre><code>swiftmailer:
transport: "%mailer_transport%"
encryption: ssl
auth_mode: login
host:      "%mailer_host%"
username:  "%mailer_user%"
password:  "%mailer_password%"
spool:     { type: memory }
</code></pre>

<p>I tried different hosts like <code>~</code>,<code>127.0.0.1</code>,<code>localhost</code>,etc in the <code>mailer_host:</code> parameter.
But mail is not sending.</p>

<p>If I use Gmail account with,</p>

<pre><code>mailer_host: smtp.gmail.com
</code></pre>

<p>the mail is sending properly.
Where am I wrong?</p>