What IP's are used for connecting to the provider / delivering mail to the provider?

Nylas has a large pool of IP addresses which are used to connect to the provider and to collect mail and deliver mail to the SMTP server.

Sometimes providers need to whitelist these IP's. This is especially common with IMAP SMTP servers.

To find these IP's the developer of the application the account is connected to needs to fetch the IP's and pass these onto the customer,.

Resources:

https://developer.nylas.com/docs/api#get/a/client_id/ip_addresses