How do shared IP pools and sending domains impact email sender reputation for ESPs?

Email marketer from GlockApps shares that while IP reputation is important, domain reputation is increasingly significant. Using a consistent sending domain and authenticating it properly can improve deliverability, even on shared IPs.

Email marketer from Sendinblue explains that sender reputation depends on factors like IP address reputation, domain reputation, spam complaints, and email authentication (SPF, DKIM, DMARC). Shared IPs can be affected by other senders, while dedicated IPs offer more control.

Email marketer from StackOverflow answers that with shared IP, your email deliverability is at the mercy of other people, while dedicated IP gives you full control, but you have to keep it clean. You need a good volume of email to keep a dedicated IP good

Email marketer from Postmark explains that sender reputation is built on various factors, including domain age, email authentication, and engagement. Domain reputation plays a crucial role, and ESPs should monitor both IP and domain reputation to ensure deliverability.

Email marketer from Reddit user shares that using shared IP pools is fine but you need to make sure your own domain is properly setup with authentication (SPF, DKIM, DMARC) so mail providers know who you are, otherwise you can get caught up with other bad senders on the same IP.

Marketer from Email Geeks explains that the tracking domain would be a data point in a reputation system and it's best practice to delegate tracking links to your own domain to control its reputation.

Marketer from Email Geeks responds that senders go to extreme measures to fully whitelabel their traffic from the ESP, like using their own domain for the 5321.MAILFROM, their own DKIM signatures, their own domain for click/open tracking, but unless you have a bad ESP it's not really that important.

Marketer from Email Geeks responds that ESP reputation can be affected by clients on dedicated domains, but less so than the effect of a client on a shared domain.

Marketer from Email Geeks explains that sending reputation is calculated using many data points, including the DKIM signing domain, the sending IPs, and the 5322.FROM domain.

Marketer from Email Geeks mentions that the ESP's domain reputation may be affected by bad behavior on their network because the ESP often hosts images or click tracking domains. Bad behavior by multiple senders could impact the ESP's domain, even for senders with good practices.

Email marketer from Litmus shares that authenticating your sending domain with SPF, DKIM, and DMARC is vital. While IP reputation matters, having a properly authenticated domain can significantly improve your email deliverability and placement, regardless of the IP pool.

Email marketer from Mailgun responds that key to sender reputation improvement is ensuring proper authentication (SPF, DKIM, DMARC), using a dedicated IP address when possible, maintaining consistent sending volumes, and monitoring engagement metrics such as opens and clicks.

Email marketer from Mailjet shares that shared IPs are cheaper but risk deliverability issues due to other senders' practices. Dedicated IPs offer more control over reputation but require careful management to avoid damaging your sender score.

Email marketer from Email on Acid explains that shared IPs carry the risk of being affected by other sender's actions, which can lead to deliverability problems. However, they also allow you to 'borrow' reputation from the other good senders.

Marketer from Email Geeks shares if you are an ESP then you really need to be signing with your domain as that is required for DKIM-based FBLs (e.g., Yahoo!) and other things, so the traffic is easily identifiable

Marketer from Email Geeks explains 5322.From is the regular From address you see in email messages (senders domain), and 5321.MAILFROM is the ESP domain (bounce address).

Expert from Email Geeks shares that if ESPs segregate by IP but not by domain and do not police their customers perfectly, they will eventually have domain problems.

Expert from Word to the Wise (Laura Atkins) shares that warming up IPs is essential and provides guidance on the ramp-up process, the importance of monitoring blocklists, and how to handle challenges like low engagement. She answers questions regarding warming IPs and how it affects reputation.

Expert from Word to the Wise shares various opinions on the increasing importance of domain reputation in comparison to IP reputation. While IP address impacts are still very real, domain authentication and reputation are becoming more critical for deliverability.

Expert from Spam Resource (John Levine) explains that small volume senders are often better off on shared IPs, as they don't have the volume to build a dedicated IP's reputation, and gives advice for senders on shared IPs.

Documentation from Microsoft shares that consistent volume from a dedicated IP builds positive reputation but also highlights that low volume from an IP (shared or dedicated) can be problematic. Senders should maintain a regular schedule.

Documentation from RFC-Editor answers that SMTP protocol defines how email is sent and specifies roles for domains used in MAILFROM (5321.MailFrom) and From (5322.From) addresses. Correct setup of these domains and related DNS records (SPF, DKIM, DMARC) is important for building sender reputation and trust with receiving mail servers.

Documentation from Amazon Web Services explains that dedicated IPs offer more control over sender reputation. Using a shared IP pool carries the risk of being impacted by the sending practices of other AWS customers.

Documentation from SparkPost answers that using a shared IP means your reputation is partly determined by other senders on the IP. A dedicated IP grants more control but requires consistent volume and careful management to maintain a good reputation.

Documentation from Mailchimp states that warming up an IP address gradually increases your sending volume to build a positive sender reputation with ISPs. This is especially crucial when transitioning to a dedicated IP but also relevant when using shared IPs, to demonstrate consistent and responsible sending practices.

Documentation from Google Workspace Admin Help explains that when using a shared IP address, the sender's reputation is affected by the sending habits of everyone sharing the IP. Poor practices from others can negatively impact deliverability.