The consensus from experts, marketers, and documentation is that Gmail considers both domain and IP reputation for email deliverability, though domain reputation is increasingly prioritized, especially with proper authentication (SPF, DKIM, DMARC). IP warming is crucial for new IPs to establish a positive sender reputation by gradually increasing sending volume, starting with engaged subscribers while carefully monitoring deliverability metrics. Sender reputation, assessed by ISPs based on sending behavior, directly affects inbox placement. Maintaining consistent sending practices, implementing email authentication protocols, and practicing list hygiene are critical for optimizing deliverability and protecting against spam filters and email-based attacks.

The provided answers indicate that Gmail considers both domain and IP reputation for email deliverability, although domain reputation is increasingly prioritized, especially for authenticated senders. IP warming is essential for new IPs to establish trust with ISPs by gradually increasing sending volume, starting with engaged users and monitoring bounce rates. Sender reputation, a score assigned by ISPs based on sending behavior, influences inbox placement. Factors impacting deliverability include sender authentication (SPF, DKIM, DMARC), engagement metrics, and list hygiene.

The provided answers from Email Geeks and Word to the Wise emphasize that Gmail considers both domain and IP reputation, although the specific weight of each is not definitively known. IP warming is crucial when introducing new IPs, requiring a gradual increase in sending volume to establish legitimacy and avoid spam filters. This process involves monitoring deliverability metrics and adhering to best practices, including proper authentication, to build a positive sender reputation with mailbox providers. Consistency in following best practices ensures long-term success.

The documentation highlights that Gmail, along with other mailbox providers, uses sender reputation to filter spam and abusive emails. Building a good sending reputation, especially when using new IP addresses, involves IP warming - gradually increasing email volume while monitoring deliverability. Key to achieving good reputation is consistent sending practices, proper email authentication (SPF, DKIM, DMARC), and maintaining list hygiene. SPF and DMARC are crucial protocols for authenticating emails and preventing spoofing.