550 messages should have one or no content-type headers, not 2

Even without SwiftMailer the problem consists.

How’s SwiftMailer working for you on MailPoet? Are you aware that you can setup SendGrid straight into MailPoet, right? Make sure to check the “webAPI” option on the Send With tab.

The WebAPI is on, smtp.sendgrid.net is the hostname. But still the problem exists. SwiftMailer is de-installed.

I’m also getting the same problem when using Mailpoet with Sendgrid. When sending a test email from within Mailpoet settings, the message says it was successful, but the email never arrives. When you check within the Sendgrid console you find that the emails bounced with the “550 Messages should have one or no Content-Type headers, not 2” message.

I’m getting the same problem with MailPoet and SendGrid.

I got around the problem by moving from SendGrid to ElasticEmail.

Hi There,

I am experiencing the same problem here. Unfortunately there is no documentation to be found on this subject at Mailpoet. Is there any way to prevent double Content-Type headers?

Thanks,

Juri

I’m getting the same problem with MailPoet and SendGrid.

Could you try to uncheck the “webAPI” option on the Send With tab and trying again?

If it still doesn’t work, the easier solution is to change SendGrid to ElasticEmail.

Thanks!

I got it to work with Mandrill…

Closing this topic.