Email deliverability is the ability to deliver an email to a recipient's inbox in a timely manner.| postmarkapp.com
IP reputation is the level of trust inbox providers place on your sending IP (Internet Protocol) address and important factor in guaranteeing email deliverability.| postmarkapp.com
DKIM (DomainKeys Identified Mail) is an email authentication method that uses public-key cryptography to sign emails and verify that the message body and attachments were not altered in transit.| postmarkapp.com