With the Mailjet SMTP Relay you can send emails in an easy way, requiring minimum integration effort on your side.
The SMTP Relay is useful if you have an existing solution for transactional emailing by SMTP or if you cannot use the Send API. Using the SMTP relay, you have to take care of email headers, MIME type handling and completely format and personalize your message content.
The best and fastest way to use the SMTP Relay is to have your own local mail server relaying messages to the Mailjet SMTP. Your local mail server will give you reliable management of the messages and connections between our 2 systems. In case of breakage in the connection, your mail server will properly handle the error and retry sending your messages.
In case you don't have a local mail server, you can still use the SMTP Relay by using one of the many SMTP libraries available or configuring your exiting system (frameworks, CMS, CRM...). However, some of these libraries or systems can lack the advanced error handling necessary to queue and resend the messages in case of an error. The use of Send API can be a better choice as it requires less interactions between our systems and limits the risk of failures. The error handling is also a lot simpler with the API as we are managing the delivery and queuing of your messages for you.
Using Mailjet's SMTP servers to send your transactional emails is very simple. All you have to do is update your SMTP server settings to use our server as a "relay" or "smarthost" with the credentials provided by Mailjet. The credentials are your $MJAPIKEYPUBLIC as a login and $MJAPIKEYPRIVATE as a password.
You can find your SMTP credentials in your Account Setup page.