The latest update to RSVPMaker includes some tweaks for better compatibility with plugins for improved email delivery and particularly the SendGrid plugin, which I may start standardizing on for my own RSVPMaker projects going forward.
The plugin improves delivery of basic transactional emails such as password reset messages. RSVP notices to site administrators and confirmation messages to site visitors can come along for the ride. This is API integration with the SendGrid transactional delivery email service, which is different from connecting with SendGrid via SMTP. Instead of setting the SMTP options on the RSVPMaker settings screen, make it “None – use wp_mail()” — the SendGrid plugin will override the default wp_mail() function.
The SendGrid mass email delivery service offers accounts that are free for up to 12,000 messages per day. If you have more activity than that connected to your site, hopefully you can afford to to pay for the service. Paid accounts include additional features, but even the free version should give you more reliable delivery of email.
After setting up your account, you will create an API key in the settings section of the SendGrid dashboard. The service will generate a long alphanumeric key that you will need to record in the SendGrid settings screen in WordPress.
Include a default email from name and sending address to be used for password resets and such. You can ignore most of the rest of the fields for setting a template etc, which are not relevant for the use of this plugin with RSVPMaker. Content-type should be set to text/plain for compatibility with plaintext messages such as password resets (this will not prevent RSVPMaker from sending HTML formatted content).
SMTP Plugins
The latest RSVPMaker release should also work better with various plugins that alter the wp_mail() function to make it work with an SMTP server. However, I can’t necessarily test for these. When I tested it in combination with one called Easy WP SMTP, it seemed to override some of the email header settings in the RSVPMaker code so that RSVP notifications came in as “from” the email address set in the plugin, rather than the email address of the attendee.
SendGrid Versus MailChimp
RSVPMaker supports another email delivery service, MailChimp, for mailing list integration, suitable for sending out event invitations or email newsletters. Although there is some overlap between the way SendGrid and MailChimp are used, SendGrid is best known for its capability of sending large numbers of transactional emails like registration or order confirmation messages.
One difference is that with SendGrid, we’re not typically broadcasting to a predefined list or relying on the service to manage unsubscribe requests. Like any other email service provider, they will monitor you to make sure you’re using the service responsibly and not spamming people. RSVPMaker only supports sending messages to site administrators, event attendees, and members of your website (with user accounts), so you shouldn’t be using it to email anyone who is not expecting to hear from you.
MailChimp actually has a transactional email service of its own called Mandrill, but I haven’t worked with it yet. Mandrill currently offers a free trial, but not a free tier of service.