Can one dedicated IP be mapped to multiple sub-domains for email?

Email marketer from Reddit explains that it's perfectly acceptable to use one dedicated IP for multiple subdomains, especially if they're all related to the same business and sending similar types of emails. However, they caution to monitor deliverability closely.

Email marketer from Email Marketing Forum shares that while technically possible, mapping multiple subdomains to a single IP can create challenges with reputation management. If one subdomain develops a poor reputation, it can affect the deliverability of emails sent from other subdomains using the same IP.

Email marketer from Email Deliverability Forum warns that using a single dedicated IP for multiple subdomains increases the risk of all subdomains being blacklisted if one subdomain engages in spammy practices.

Email marketer from Email Service Provider Blog explains that if you have sufficient sending volume for each subdomain, using separate dedicated IPs can provide better control over reputation. However, for low-volume subdomains, sharing an IP might be more practical.

Email marketer from StackExchange shares that it depends on the purpose of the subdomains. If they're for drastically different types of email (e.g., transactional vs. marketing), separate IPs might be better. If they're closely related, a single IP can work.

Email marketer from Mailjet shares that using subdomains for different types of emails (transactional, marketing) helps segment your sending reputation. While technically multiple subdomains can share an IP, it's crucial to monitor each subdomain's reputation independently.

Email marketer from Email Marketing Blog suggests segmenting IPs based on the type of email being sent. Transactional emails should be on a different IP than marketing emails to protect the reputation of critical transactional communications.

Email marketer from Reddit stresses the importance of warming up IPs correctly when using multiple subdomains. They recommend starting with small volumes and gradually increasing, monitoring deliverability metrics closely.

Email marketer from Email Geeks shares that while it’s a recommendation to separate each subdomain into their own subdomain/IP pairing, it doesn’t always work if you don’t have volume to support it. A potential issue is that a subdomain for a less desirable stream can impact the IP reputation, which directly impacts the others.

Email marketer from SendPulse shares that using subdomains allows you to isolate the reputation of different email streams. If one subdomain has deliverability issues, it won't necessarily impact the reputation of other subdomains using the same IP.

Expert from Email Geeks confirms it's okay to use more than one dedicated IP mapped to one sender domain, and then warm up each pair gradually.

Expert from Email Geeks explains that you can mail multiple 821.From domains off a single IP, and use multiple IPs for a single 821.From. You just shouldn’t start messing with the server HELO.

Expert from Spam Resource explains that while technically possible to map multiple subdomains to a single dedicated IP, doing so can create a single point of failure for your email reputation. If one subdomain is compromised or develops a poor reputation, it can negatively impact the deliverability of all subdomains using that IP.

Expert from Word to the Wise, Steve Jones, responds that, although the question is about IPs and Subdomains, they recommend using a good subdomain strategy as part of the answer. The subdomain strategy is dependant on the customer, as such they cannot give a single answer.

Expert from Email Geeks shares that a baseline assumption is that you'll need to warm up each IP/authenticated-domain pair separately. That's often not true, but doing it won't hurt, other than taking some time and effort.

Expert from Email Geeks explains that you'll need to ramp up traffic on the new IP gradually ("warm it up"), same as you would for any other mail stream. At some recipient ISPs the fact that there's an existing mail stream with good reputation sending using the same authenticated domain will help; at others it won't.

Documentation from Amazon Web Services explains that using a dedicated IP address with Amazon SES allows you to control your sending reputation. AWS recommends carefully monitoring your sending metrics and following best practices to maintain a good reputation.

Documentation from Google Postmaster Tools explains that senders using dedicated IPs should ensure proper authentication (SPF, DKIM, DMARC) and maintain a low spam complaint rate to establish a good reputation with Gmail.

Documentation from SparkPost explains that when introducing a new IP address, it's essential to warm it up gradually to establish a positive sending reputation. This involves steadily increasing sending volume and monitoring deliverability metrics.

Documentation from RFC Editor explains that the HELO/EHLO domain should resolve to the IP address used for sending. Mismatches can negatively impact deliverability.

Documentation from Microsoft Learn explains that using a dedicated IP address gives you full control over the sender's reputation. This means you're responsible for maintaining its good standing by following best practices for sending email and avoiding spam traps.