Email 402 Status Code

If you receive a 402 status code when sending emails, this means that the message was blocked due to spam content in the message.

This occurs when the recipient's email server detects the message as spam. To resolve this issue, the client will need to reach out to their email administrator to whitelist these emails. 

See this link for more information regarding email status codes:

https://developer.nylas.com/docs/connectivity/email/send-emails-with-nylas/#sending-errors