Increase your email reputation with IP warming

Getting started

Adobe requires customers to share their configuration to help the Adobe Deliverability team understanding your unique program. The questions that we ask are designed to help the Adobe Deliverability team get a sense of your sending reputation and your email volume. Without a concrete understanding of your business model, email marketing goals and reputation metrics, we won’t be able to customize strategy and there is risk of deliverability issues.

At the outset, you’ll be assigned your own dedicated IP (Internet Protocol) addresses. In the context of sending email, an IP address is the route that’s used to deliver your email messages to your customers. IP addresses and domains are used to identify senders on a network to the receiving ISPs. Adobe assigns the appropriate number of dedicated IP addresses for sending emails, based on your sending volume, email programs, data segmentation practices, and your contract.

Related topics:

IP Warming: Why is it done? why-ip-warming

Internet Service Providers (ISPs) or Mailbox Providers (MBPs) take precautions when they detect an unfamiliar IP and sending domain. This is standard procedure associated with any new sending IPs, regardless of sender type. ISPs/MBPs put the IP and sending domain under high scrutiny to determine if the emails being sent from this IP and domain are spam or not. This is standard procedure associated with any new sending IPs, regardless of sender type.

ISPs examine carefully the sending volume, send frequency, complaints, and bounce rates generated from these mailings. These are all checked closely because they are indicators of reputation of the sender – be it good or bad.

Naturally, this process of examining these data points takes time, and it cannot be achieved in a day or two. Reputation is built over time. This process is like letting a stranger in your home. Would you have reservations about having someone you have never met enter your home?

Very likely the answer is yes. You would want to analyze this person and their motives. Do they mean harm? Are they a threat? ISPs do the same to protect their network from malicious or unwanted traffic. Positive reputation metrics help you go a long way in a successful IP warming process. That’s why we stress the importance of starting off with sending small email volumes and starting to send to your highly engaged customers first. For more on this, see Targeting criteria when sending new traffic.

Sending large quantities of email from a brand new IP or IPs right out of the gate is a poor practice and will likely cause you some deliverability difficulties. It’s important to note that even if you start to send small volumes and gradually increase them as recommended, it is still necessary to follow email best practices.

Permission to mail (Explicit Opt-In)

This is the most important component of managing and growing a subscriber email list. As anti-spam laws grow and become more comprehensive internationally, it should be a marketer’s primary focus to ensure that they have received explicit (or express) consent from each subscriber on their list. That is, each subscriber has actively agreed to receive emails from your brand. This differs from implicit consent where a person is added to an email list after taking an action that was not explicitly signing up for an email program.

Learn more on Adobe’s Acceptable Use Policy.

Reputation Metrics: What are ISPs looking for?

ISPs use sophisticated technology in order to make educated decisions about whether or not to deliver email they’re receiving from external networks. They sometimes have complicated and proprietary algorithms in their toolset to aid them in this process.

Some of the data points examined are:

  • Spam trap hits
  • Blocklist hits
  • Email bounces
  • Subscriber engagement

ISPs require specific technical configurations that align with their policies and best practices. Adobe configures your IPs and delegated subdomains to identify you as a responsible and trusted sender. This is called email authentication. Authentication helps receivers validate whether a sender has the rights to send from that IP or domain.

Authentication allows the ISPs to validate that the company sending from a domain or IP has the right to do so. It’s essentially done to prove your identity and to make sure that you are not pretending to be someone else, and that someone else is not pretending to be you.

At Adobe, we will configure SPF and DKIM by default and we will configure DMARC by request. ISPs reference SPF and DKIM as the primary forms of authentication. Many ISPs are also incorporating DMARC (Domain-based Message Authentication, Reporting & Conformance) into their filtering decisions. Unauthenticated emails aren’t necessarily blocked, but they go through additional filtering.

IP Warming: What to expect

Throttled or blocked mail

Spammers are sending from new IPs all the time – they will burn through a pool of IPs until they get shut down and repeat the process on another pool of IPs. As a result, ISPs treat traffic being sent from new IPs carefully. They block IPs from sending large amount of email because they suspect that this is malicious activity being executed by spammers.

Consequently, it’s not uncommon to receive deferral or throttled messages when you start mailing from your new IPs. After a few retries, the message is usually accepted and delivered.

Achieving a normal flow of traffic through to the ISPs that defer new senders may take a few days. Even so, do not stop sending mail – continue to focus on only sending to your most highly engaged email subscribers.

In rare cases, the ISP blocks the new sender. Adobe is monitoring your account, and if such a block is suspected, will reach out to the ISP to try and help remedy the situation in the best possible way.

Remember that consistency is key here. Irregular sending volume patterns and infrequent mailing patterns will cause some deliverability challenges along the way.


Complaints occur when a subscriber labels an email as spam through their email program. This sends a notice to the ISP about the complaint activity. If there are enough of these complaints that come into the ISP, that ISP will act to protect its customers – possibly block many emails from getting to the subscribers or direct a portion of emails to the bulk folder as opposed to subscribers’ inboxes. If your delivery issue is caused by complaints, it’s important to determine why recipients are complaining.

Subscribers complain for various reasons. Sometimes a subscriber doesn’t want to receive any more email from you, perhaps because they feel they’re getting too many messages on the same topic, they weren’t expecting the message, or don’t remember signing up to receive your emails.

Data validity

Hard bounces occur when you send to an undeliverable address at an ISP. An address can be undeliverable for many reasons, such as a mistake in typing the address or mailing to an address that was previously active but has been closed or terminated after a period of inactivity.

If you encounter a substantial number of hard bounces, it’s important to understand why. Review how the addresses were collected and confirm that permission was given. Sometimes people close their email account and don’t notify those who have that address on their marketing list.


ISPs look for consistent volume and good data quality. You will slowly and steadily increase traffic over the next four to eight weeks. Sometimes ramp-ups require more or less time based on your volume and goals, but typically, it is at least an 8-week process.

Email traffic should deploy in a slow and steady progression, increasing each week until the entire list has been sent. In addition, each segment will follow the schedule until completion. Start with the most recent subscribers first, and finish with the least engaged subscribers last. Please also note that certain ISPs may require a more customized approach due to how they handle new traffic.

Learn more on engagement.

Stay the course

You may be tempted to rush the process of IP warming by sending more volume than is recommended, neglecting to spend time identifying your most-engaged subscribers and failing to mail these subscribers first in an effort to build a positive reputation. Please resist this urge! It will not help you in the long term.

It is very important to start mailing your highly-engaged (with email!) subscribers only for the beginning stages of IP warming. These customers are your most valuable and their propensity to open your emails will help to start showing ISPs that you’re a marketer who sends mail that is interesting and sought-after. It also shows ISPs that you are playing by the rules and following best practices.


Remember: IP Warming is a marathon - not a sprint! While the process may seem burdensome and time-consuming, it would be more work to try to repair a reputation damaged by not following tried and true email best practices.

The better your sending practices are, and the higher your reputation scores are with ISPs, the more likely your emails will be delivered. IP warming and ramping up, along with following the best practices for the design of your mailing, will help optimize your inbox delivery.

Our global deliverability team is your partner in this process and will help you during this IP warming phase to position you for success.