Email deliverability describes the ability of a message not only to reach the receiving mail server, but also to arrive successfully in the recipient’s inbox.
Delivery and deliverability are different
A server accepting a message does not guarantee inbox placement. The receiving system may still place it in spam or apply additional filtering.
Sender reputation
The historical behavior of the sending IP address and domain can influence how mailbox providers evaluate new messages.
SPF, DKIM and DMARC
Correct authentication records help receiving systems verify that the message originated from an authorized source.
List quality and sending behavior
Repeated delivery attempts to invalid addresses, high complaint rates and sudden volume changes can negatively affect deliverability.
Content matters too
Misleading subject lines, suspicious links and overly aggressive marketing language may increase filtering risk.
Learn more in our SPF, DKIM and DMARC guide.