When warming up new IPs, is it better to warm up per domain or per MX?
Summary
What email marketers say9Marketer opinions
Email marketer from EmailVendorSelection explains that a good list and email setup with a solid sender reputation is the best way to warm-up an IP address. They share it is a waste of time and money warming up a list of invalid email addresses.
Email marketer from Mailjet explains that warming up per domain is often simpler for smaller senders. They share that focusing on sending to engaged users helps build a positive reputation regardless of the method.
Email marketer from Email Geeks explains that warming up MXs is more complicated and offers less control. A downside of warming domains is potential volume limitations for specific filters like Microsoft's.
Email marketer from Reddit shares that warming up per domain can be easier to manage, especially if you're not sending large volumes to each domain. He warns if you are a high volume sender then MX might be better to focus on.
Email marketer from GlockApps suggests splitting your total email volume into smaller batches and gradually increase the batch size daily. They share that you should start with your engaged subscribers.
Email marketer from Omnisend explains that there are a number of methods to follow when warming up an IP. These include starting with the highest engaged customers; segment by engagement and send separate campaigns; set up SPF, DKIM, DMARC; and keep a close eye on your deliverability to help you improve your sending reputation.
Email marketer from MailerQ suggest using separate IP addresses for your marketing campaigns and transactional mailings. This ensures that your transactional email doesn’t suffer deliverability issues.
Email marketer from SparkPost suggests starting with your most engaged subscribers and gradually increasing volume. SparkPost doesn't explicitly advocate warming up by domain or MX record, but recommends focusing on recipient engagement and list quality during the warm-up phase for optimal deliverability.
Email marketer from Email Geeks shares that when automating for ESPs, they used MX; for clients, they used domain or rough volume. All methods work depending on time investment.
What the experts say3Expert opinions
Expert from Spam Resource explains that it's essential to monitor deliverability and adjust the warm-up strategy as needed. They suggest focusing on building a positive sending reputation by sending to engaged subscribers.
Expert from Email Geeks responds that warming up per-MX takes more effort, and since you are aiming for a rough ramp-up, warming up per-domain is sufficient.
Expert from Word to the Wise shares that there is no one-size-fits-all approach to IP warming. They explain that good list hygiene, engagement, and proper authentication are more important than strictly adhering to per-domain or per-MX strategies. They suggest monitoring and adjusting the warm-up approach based on the data.
What the documentation says3Technical articles
Documentation from Twilio SendGrid explains that IP warming involves gradually increasing sending volume to build a positive reputation with ISPs, emphasizing consistent volume and engagement metrics. They don't directly specify per-domain vs. per-MX, but imply focusing on overall sending health.
Documentation from Google suggests ensuring you have all authentication methods in place. They share that a high Spam Rate might result in your email being delivered to your recipients’ Spam folders, or might even be blocked completely.
Documentation from Amazon SES suggests a gradual warm-up, monitoring sending limits, and ensuring low bounce and complaint rates. They do not suggest if it should be per domain or MX but highlight the importance of maintaining a good sender reputation throughout the warm-up process.