Freshjet

People use SMTP or transactional email to prevent their email sent by wp_mail() fall into spam folder. And if you are using Mailjet as your transactional email, this plugin is probably the most convenient way to use Mailjet transactional email in WordPress.

Freshjet provide default wp_mail() functionality but super-power it with Mailjet. It’s a drop-in replacement for wp_mail(). If you just send email without extra customization, likely you don’t need to change your existing code.

And.. Freshjet supports Mailjet Passport Template. For documentation, visit Freshjet GitHub repository

Through the WordPress administrative area:

• From WordPress administrative area, go to Plugins -> Add New
• Search for Freshjet
• Install and then activate it
• Visit this page to see your Mailjet Keys.
• Insert your API Public Key (SMTP username) and API Secret Key (SMTP password) in yoursite/wp-admin/admin.php?page=freshjet

Download manually:

• Download the plugin from WordPress plugins page
• Upload to your wp-content directory
• Activate it from Plugins menu in admin area
• Visit this page to see your Mailjet Keys.
• Insert your API Public Key (SMTP username) and API Secret Key (SMTP password) in yoursite/wp-admin/admin.php?page=freshjet

1. 

   Admin Screenshot

0.6.6

• Tweak: bulk_mail() now support Mailjet’s Transactional Template
• Tweak: Handler for string header

0.6.5

• Bugfix: correcting typo in class-email.php from $opts to $this->options. Thanks Bastien Martinent for letting us know here

0.6.4

• Settings: add blank option to template selection
• Bugfix: wp_error on wp_remote_get response was not handled
• Bugfix: headers support

0.5.4

• Distinguish the master key and sub-account key

0.5.3

• wp_mail() drop-in replacement
• Provide support for Mailjet’s Transactional Passport Template