If you’re building WordPress websites for high profile companies with many different needs and site interactions, you really need to extend the transactional email process.

The aim with this is to have more control over the look of emails sent by actions taken by users and improve the chance that these important emails reach their intended recipients.

To achieve this, offload the email sending to a third-party email sending service that focuses on email deliverability.

Here is a list of them I put together with my reviews

Another big benefit: Analytics

Normally your WordPress install is doing all this stuff and you could check the logs and copy yourself on emails but you never know whether they get to the intended recipient. Mandrill will solve this for you. They provide an amazingly simple interface that shows you every email sent, whether and when it was opened and even whether an email recipient clicked on a link in the email.

Resources / links:

Here.