How Nylas Sends Emails
Nylas does not send emails from our servers.
Instead, once you make the API call to send an email, we connect to the email server's SMTP with the user's credentials and upload the email for delivery.
Then one of three things can happen:
- The email is accepted for delivery and we return a 200 response to your application.
- The email is rejected by the email server. We'll pass along the rejection code and error message from the provider.
- The email is delayed. The delayed email can be because the email server is under heavy load or we are trying to upload a large attachment. We recommend waiting three minutes for the request to time out before sending any new API calls.
An email delivery service sends emails on behalf of other domains. If an email administrator is asking for the following information from Nylas, we do not function as an email delivery service. This means we do not manage:
- Dealing with Spam - While Nylas is not an email provider, we have a few tips on dealing with messages being marked as spam.