How long does it take to warm up a dedicated IP?

The length of the IP warm-up process varies, but typically ranges from four to eight weeks. It depends on factors like your sending volume, the quality of your recipient list, and how ISPs respond to your sending behavior. High engagement and positive feedback can sometimes shorten the process, while issues like bounces or complaints may extend it.

Is IP warming truly necessary for a new dedicated IP?

Yes, it is crucial. Attempting to send high volumes from a new dedicated IP without warming it up will almost certainly lead to your emails being filtered as spam or blocked. ISPs (Internet Service Providers) use reputation to decide whether to accept emails, and a new IP has no reputation initially, making the gradual warm-up essential to build trust.

How do I monitor the progress of my IP warm-up?

Monitor key metrics such as open rates, click-through rates, bounce rates, and spam complaint rates daily. Use DMARC reports for authentication failures and keep an eye on blocklist (blacklist) services . If you see a sudden increase in bounces, complaints, or deferrals, reduce your sending volume and investigate the cause.

Should I warm up transactional and marketing emails separately?

Yes, generally, it is best to separate transactional and marketing emails, ideally using different dedicated IPs for each. Transactional emails have higher engagement rates and can help build a very strong initial reputation. Marketing emails, which might have lower engagement, can then leverage this established reputation without negatively impacting critical transactional flows.

What are the best practices for dedicated IP warm-up? - Sender reputation - Email deliverability - Knowledge base

Embarking on email marketing with a dedicated IP address is a significant step, offering greater control over your sender reputation. Unlike shared IPs, where your reputation is influenced by other senders, a dedicated IP gives you direct ownership. However, this control comes with the crucial task of IP warming, a process vital for building trust with Internet Service Providers (ISPs).

IP warming is essentially a systematic way of introducing your new IP address to ISPs. It involves gradually increasing the volume of emails sent over a period, allowing ISPs to observe your sending behavior. This gradual ramp-up helps them recognize you as a legitimate sender, not a spambot, and assign a positive reputation to your IP.

If you rush this process, you risk triggering spam filters, getting blocklisted, and severely impacting your email deliverability. A carefully executed warm-up builds a strong sender reputation from day one, ensuring your emails reliably reach the inbox.

The foundation of a successful warm-up

Before you even think about sending your first email from a new dedicated IP, ensure your technical infrastructure is solid. This lays the groundwork for a smooth warm-up and long-term deliverability success.

Your sending list must be meticulously cleaned and verified. Sending to old, inactive, or invalid email addresses can lead to high bounce rates and spam complaints, which are detrimental to your new IP's reputation. Focus on engaged, permission-based subscribers who are likely to open and click your emails.

Consistency is key. During the warm-up period, maintain a steady sending volume and frequency. Avoid sending large bursts of emails followed by long periods of inactivity, as this can look suspicious to ISPs. Think of it like building a consistent exercise routine, steady progress yields better results.

Also, ensure your domain's authentication records are correctly set up. This includes SPF, DKIM, and DMARC. These protocols verify your identity as a sender and are fundamental for establishing trust.

Technical prerequisites

SPF records: Ensure your SPF record includes all authorized sending IPs and services.
DKIM setup: Properly configure DKIM to digitally sign your outgoing emails.
DMARC policy: Implement a DMARC record to monitor and enforce email authentication.
Reverse DNS (rDNS): Ensure your IP address has a valid rDNS entry that matches your sending domain.

Crafting your warm-up schedule

The core of IP warming is a carefully planned schedule that gradually increases your email volume. You should start with a very low volume and incrementally ramp up over several weeks, typically four to eight. This allows ISPs to slowly build a positive reputation for your new IP.

During the initial phase, prioritize sending emails to your most engaged subscribers. These are individuals who have recently opened or clicked your emails. Transactional emails (e.g., password resets, order confirmations) are ideal for warming up a new IP because they typically have very high engagement rates and are expected by recipients. This helps establish a positive rapport with ISPs from the outset. You can read more about warming up new IPs for transactional emails.

Week	Daily Volume	Email Type	Target ISPs
1	100-500	Transactional, highly engaged contacts	Gmail
2	500-2,000	Transactional, recent marketing engagement	Outlook
3	2,000-5,000	Marketing messages, segment by domain	Yahoo
4-8	5,000+ (gradual increase)	Full marketing campaigns	All domains, monitoring closely

Initial warm-up sending

During the early stages of IP warming, your focus should be on building a positive sending reputation. This means prioritizing quality over quantity and aiming for the highest possible engagement rates.

Audience: Send only to your most active and engaged subscribers, such as those who have opened or clicked an email in the last 30-90 days.
Content: Prioritize transactional emails, welcome series, or highly anticipated content that users expect and are likely to open.
Volume: Start with very low volumes, gradually increasing daily based on positive engagement metrics and no signs of issues.

Post warm-up sending

Once your IP is warmed up and has established a solid reputation, you can begin to send your full volume of marketing and promotional emails. The goal here is to maintain the positive reputation you've built.

Audience: Broaden your audience to include all engaged subscribers, segmenting as needed for targeted campaigns.
Content: Diversify your content to include marketing newsletters, promotions, and other relevant communications.
Volume: Maintain a consistent daily or weekly sending volume close to your average expected sends. Avoid sudden, massive spikes.

Monitoring and adapting your strategy

Throughout the IP warm-up period, rigorous monitoring is non-negotiable. You need to pay close attention to key email metrics to gauge how ISPs are reacting to your new IP. Look at open rates, click-through rates, bounce rates, and spam complaint rates.

Keep a sharp eye on deferrals, which indicate that an ISP is temporarily rejecting your emails. While some deferrals are normal during warm-up, a sudden spike could signal an issue. Similarly, monitor blocklist (blacklist) status. Being listed on a blocklist can severely impede your deliverability.

Identifying and addressing red flags

High bounce rates: If you see an unusual increase, pause sending and re-verify your list. Ensure you're not hitting too many unknown users.
Spam complaints: Even a small number can be problematic. This indicates your recipients don't want your emails, or your content is triggering spam filters. Analyze content and list segments.
Low engagement: If opens and clicks are low, it might be a sign that your content isn't resonating or your targeting isn't precise enough for the warm-up phase.
Deferrals: Be prepared for some, especially from Hotmail (now Outlook). If they persist, you might need to slow down your sending to that particular ISP.
Blocklisting (blacklisting): If your IP appears on a major blocklist, stop sending immediately and follow their delisting procedures. This is a clear sign to adjust your strategy.

Sustaining deliverability long-term

The warm-up process isn't a one-time event, but rather the establishment of long-term sending habits. Once your IP is fully warmed up, the goal shifts to maintaining that positive reputation. This requires continued diligence and adherence to best practices.

Regularly clean your email list to remove inactive subscribers, hard bounces, and known spam traps. Engaging only with active recipients ensures your sender reputation remains strong. Continuously monitor your engagement metrics. Consistent high open and click rates signal to ISPs that your emails are valued.

Deliver high-quality, relevant content that your subscribers expect. Personalized and valuable emails lead to higher engagement and fewer complaints. Ensure you provide a clear and easy unsubscribe option in every email, as this can reduce spam complaints. Following these practices will help your dedicated IP maintain excellent deliverability for the long haul. More details on consistent sending for dedicated IPs can be found on AWS SES documentation.

Views from the trenches

Best practices

Segment your audience by email domain and gradually increase volume to each domain individually.

Start by sending only to your most engaged subscribers who have opened or clicked recently.

Prioritize transactional or highly anticipated content during the initial warm-up phase.

Common pitfalls

Rushing the warm-up process by sending too much volume too quickly to a new IP.

Sending to unengaged or old email lists, leading to high bounce rates and spam complaints.

Ignoring early warning signs like increased deferrals or a sudden drop in open rates.

Expert tips

Monitor unique open rates closely, aiming for 15% or higher to indicate strong reputation building.

Distribute your daily email volume throughout the day instead of sending it all at once.

Keep automations on a shared IP pool or pause them until the dedicated IP is fully warmed up.

Marketer view

A marketer from Email Geeks says that SendGrid's warming schedule is generally reliable, and recommends segmenting sends by domain, such as Gmail, Hotmail/Outlook, and Verizon Media Group.

2019-08-01 - Email Geeks

Marketer view

A marketer from Email Geeks says it's crucial to begin sending to recipients who are most likely to engage, focusing on your most engaging content within a 30-day engagement window, and expanding it incrementally.

2019-08-01 - Email Geeks

Building lasting deliverability

Warming up a dedicated IP address is an investment in your email marketing future. It's a process that demands patience, meticulous planning, and continuous monitoring, but the payoff is significant: reliable inbox delivery and a strong sender reputation.

By adhering to these best practices, from setting up proper authentication to carefully scaling your sending volume and analyzing performance metrics, you'll establish your dedicated IP as a trustworthy sender, maximizing your email campaign effectiveness. Remember, a well-warmed IP is a cornerstone of successful email deliverability.