Outlook

You can use SMTP+ as your outgoing mail server in Outlook. Here is how to do so.

You are done!

WordPress

There are many WordPress plugins that allow you to use an external SMTP server. For a list, see: http://wordpress.org/extend/plugins/search.php?q=smtp

For example, you could choose WP Mail SMTP: http://wordpress.org/extend/plugins/wp-mail-smtp/

Once you've installed the plugin, create a SMTP+ user and enter those credentials in the plugin settings.

Please note:

Magento

How to use MailUp as your SMTP relay service for a Magento-powered ecommerce store.

Your custom application

See: Using SMTP relay from your application

Related articles