When should I use a shared IP address over a dedicated IP address for email sending?
Summary
What email marketers say13Marketer opinions
Email marketer from GMass Blog responds that if you aren't ready to send frequently and consistently, a shared IP is often a better option. If you use a dedicated IP inconsistently, your deliverability could suffer.
Email marketer from SendGrid Blog shares that when starting with email marketing, a shared IP is useful before migrating to a dedicated IP due to the need to 'warm up' a dedicated IP slowly to build reputation.
Email marketer from HubSpot discusses that for senders who are sending under 50,000 emails, it is better to use a shared IP address. If you have a sudden increase of email volume, it is better to start off using shared IP addresses to gain a good IP reputation and then move to a dedicated IP address.
Email marketer from ActiveCampaign shares that new businesses or small marketing teams, may want to start with a shared IP, so you can establish a solid sending reputation without the added pressure of maintaining a high sending volume or perfect IP address health.
Marketer from Email Geeks states that using a shared IP to send emails that a client doesn't want to risk their organizational domain's reputation with is essentially "spamming" and should be avoided, because their main domain will likely take a reputation hit because of their email activities elsewhere.
Marketer from Email Geeks explains another option is that the sender is suspicious of the ESP and think the ESP purposely gave them the worst possible dedicated IP. Senders often have issues recognizing responsibility for the IP reputation, and they might try shared IPs to "prove" they can get better results. They DO get better results, since the shared traffic is offsetting the trash such a sender could be producing, leading them to believe the ESP was prejudiced.
Marketer from Email Geeks suggests it sounds like the sender is shifting recourse and reputation issues from their Dedicated IP for a less than ideal send.
Email marketer from Email Marketing Forum responds that a shared IP is fine if you're sending low volume, as it's hard to get enough sending reputation on a dedicated IP if you're not sending enough volume.
Email marketer from Reddit explains that shared IPs are helpful when you're first starting out, you may not have the email volume needed to properly 'warm up' and maintain a dedicated IP. If your volume is low and sporadic, shared IPs are typically a better place to start.
Marketer from Email Geeks shares it could be that the content really is different from what they usually send and they're worried that it will harm their existing IP's reputation, leading to the question of why would I want to potentially tank the reputation of the shared IP with content you think will tank the reputation of your dedicated IP?
Email marketer from Email on Acid Blog shares that shared IPs are beneficial for small businesses because of their low cost, ease of setup, and immediate ability to send. However, deliverability can be affected by the sending practices of other users on the same IP.
Email marketer from Reddit explains that a shared IP is better when you're starting, as you don't have the volume to build and maintain a good reputation on a dedicated IP.
Email marketer from Mailjet Blog explains that shared IPs are suitable for senders who are just starting out, or those who send smaller volumes of emails (less than 50,000 per month). This is because the IP's reputation is shared among multiple senders, so deliverability is less dependent on your individual sending practices.
What the experts say1Expert opinion
Expert from Word to the Wise (Laura Atkins) responds that shared IPs are useful for initial testing, allowing you to test your deliverability without impacting your own reputation. It also adds using shared IP to warm up smaller sending domains.
What the documentation says3Technical articles
Documentation from Microsoft Documentation suggests that if you are sending bulk email, and are using a 3rd party ESP, they will likely be sending from shared IP addresses, meaning you need to adhere to best practices for email marketing.
Documentation from AWS Documentation explains that you should use shared IP addresses if you're new to email sending or if you send a low volume of email. Amazon SES automatically manages the reputation of shared IP addresses.
Documentation from SparkPost Documentation explains that if you are sending less than 50,000 emails a month it is best to stick with a shared IP address as you will not be generating enough volume to manage your reputation effectively.