Email message was sent successfully but not received
Sometimes, you might receive a 200 response from Nylas when you send an email message, but the recipient never receives it. This can happen for one of the following reasons:
- The sender's provider encountered an error.
- The email message bounced.
- The recipient's provider blocked the email message.
Sender's provider encountered an error
In this case, the sender's email server received the request to send the email message and returned a 200 response, but failed to send the email message.
Nylas does not send email messages itself when you make a Send Draft or Send Message request. Instead, Nylas hands the request off to the end user's provider.
If you notice that an end user's email messages are failing to send to multiple recipients, and the email messages aren't bouncing, advise the end user to reach out to their email administrator to resolve the issue.
Email message bounced
In this case, the sender's email message bounced. They should have received a "Bounced Email" message from either their email server, or the recipient's. The bounce notification usually describes the reason that the email message bounced. In most cases, the sender needs to contact their email administrator to resolve the issue.
Recipient's provider blocked email message
In this case, the recipient's provider might have flagged the email message. The recipient can check their Junk folder for the email message, or see if they have a filter that prevents the email message from reaching their Inbox.
For more information, see Nylas' best practices for dealing with spam.