Does using multiple email addresses from the same domain and IP create deliverability issues?
Matthew Whittaker
Co-founder & CTO, Suped
Published 22 Jun 2025
Updated 18 Aug 2025
7 min read
The question of whether using multiple email addresses from the same domain and IP address can lead to deliverability issues is a common one. Many businesses operate with various departments or functions, each needing its own distinct email identity, yet they all share a common brand domain and often, a single sending infrastructure (IP address). It's a practical necessity for many organizations.
My experience suggests that it generally does not, provided certain best practices are followed. The key factors influencing deliverability are not simply the number of email addresses, but rather the underlying sender reputation of your domain and IP, the consistency of your sending practices, and the proper implementation of email authentication standards.
Mailbox providers primarily assess the reputation of your sending domain and the IP address from which your emails originate. If these core elements maintain a good standing, individual email addresses under that umbrella typically inherit that positive reputation. However, this isn't a license to ignore the specifics, as improper setup or inconsistent behavior can quickly erode trust.
Sender reputation and shared infrastructure
Sender reputation is a critical component of email deliverability, dictating whether your messages land in the inbox or the spam folder. It's a composite score built on numerous factors, but for our discussion, the most relevant parts are your domain reputation and your IP reputation. When you send from multiple email addresses on the same domain and IP, these reputations are largely shared across all those addresses.
Your domain reputation is the trustworthiness assigned to your brand's domain (e.g., example.com) by mailbox providers. This reputation is built over time based on the collective sending behavior associated with that domain, regardless of the specific email address used. So, if one address on your domain engages in risky behavior, it can affect the deliverability of all others. Conversely, positive sending patterns from all addresses strengthen the overall domain reputation.
Similarly, your IP reputation is tied to the specific server (or set of servers) sending your emails. If you're using a dedicated IP address, its reputation solely reflects your sending. If you're on a shared IP, the actions of other senders sharing that IP can impact your deliverability. This is why some choose to use separate IP addresses for different types of email, even if they're from the same domain.
The role of email authentication
Email authentication protocols like SPF, DKIM, and DMARC are crucial regardless of how many email addresses you use. These protocols verify that your emails are legitimately coming from your domain, preventing spoofing and unauthorized use. Proper configuration is paramount for maintaining good deliverability, especially when multiple addresses are in use.
SPF (Sender Policy Framework) lets you specify which IP addresses are authorized to send email on behalf of your domain. DKIM (DomainKeys Identified Mail) provides a way to digitally sign your emails, allowing recipients to verify that the email hasn't been tampered with in transit. DMARC (Domain-based Message Authentication, Reporting, and Conformance) builds on SPF and DKIM, giving you control over what happens to emails that fail authentication.
Even with multiple email addresses, your domain will typically have a single set of SPF, DKIM, and DMARC records. It's essential that these records accurately reflect all authorized sending sources. If an email sent from support@yourdomain.com fails DMARC authentication, it can negatively impact your overall domain reputation, affecting emails sent from marketing@yourdomain.com as well. This is why proper email authentication is non-negotiable.
This DMARC record helps in monitoring your email authentication across all sending addresses under the domain. You can learn more about DMARC tags and their meanings.
Strategic use cases for multiple email addresses
Many businesses choose to use multiple email addresses from the same domain to segment their communications effectively. For instance, transactional emails (like order confirmations or password resets) typically have very high engagement rates and low spam complaint rates. Marketing emails, while valuable, might have lower engagement or higher complaint rates, even for legitimate sends.
Separating these email streams into distinct sender profiles (e.g., using orders@yourdomain.com for transactional and newsletter@yourdomain.com for marketing) can be a smart strategy. While the domain reputation is shared, mailbox providers can still discern patterns associated with specific From addresses. This separation helps manage expectations and user engagement.
The key is consistency and relevance. Each email address should have a clear, distinct purpose that aligns with subscriber expectations. For example, if customerservice@yourdomain.com starts sending marketing promotions, recipients might mark it as spam, negatively impacting the reputation associated with that specific sender name. This could eventually ripple up to affect the broader domain reputation. It is also important to ensure your sender and reply-to domains are consistent.
Benefits
Clear communication: Recipients know what type of email to expect from each address.
Engagement segmentation: Different engagement rates for various email types don't negatively impact others as severely.
Brand consistency: All addresses reinforce your brand identity under one domain.
Management complexity: Requires careful management of sending volume and content for each address.
Bounce handling: Ensuring all sending and reply-to addresses are deliverable to avoid bounces.
Potential pitfalls and how to avoid them
While using multiple email addresses from the same domain and IP is generally acceptable, there are specific pitfalls that can lead to deliverability issues. The biggest danger lies in inconsistent sending behavior or poor list management that could lead to your IP getting blacklisted (or blocklisted).
If any of your email addresses accrue a high volume of spam complaints, bounce significantly, or hit spam traps, this negative feedback is associated with your sending IP and domain. This can lead to all emails from that IP and domain being flagged as suspicious, even those from other, well-behaved email addresses. This is why monitoring blocklists is so important.
To mitigate these risks, maintain strict list hygiene across all your email lists. Regularly remove inactive subscribers and promptly process unsubscribes. Ensure that each email address is used for its intended purpose and that content is always relevant and engaging for its specific audience. This proactive approach helps protect your overall sender reputation.
Maintaining a healthy sending reputation
In conclusion, using multiple email addresses from the same domain and IP generally does not create deliverability issues if managed correctly. The collective behavior across all addresses defines the reputation of your domain and IP. By prioritizing strong authentication, consistent sending practices, and meticulous list hygiene, you can ensure that all your emails reach the inbox effectively.
Views from the trenches
Best practices
Maintain separate email streams for different communication types (e.g., transactional, marketing) even if using the same domain and IP.
Consistently enforce email authentication protocols (SPF, DKIM, DMARC) across all sending sources for your domain.
Prioritize list hygiene and engagement for every email address to ensure positive sender reputation.
Monitor your domain and IP reputation using tools like Google Postmaster Tools.
Common pitfalls
Mixing different email types (e.g., marketing with transactional) from the same specific email address can confuse recipients and lower engagement.
Failing to maintain list hygiene can lead to high bounce rates or spam complaints, negatively affecting the shared IP/domain reputation.
Inconsistent sending volume or sudden spikes from any address can trigger spam filters.
Not configuring or regularly checking email authentication records for all sending systems.
Expert tips
Focus on the overall domain and IP reputation, as mailbox providers primarily assess these.
If rebranding, gradually transition email addresses and maintain consistent sending behavior.
Set up DMARC monitoring to gain visibility into authentication and delivery of all emails.
Even if emails redirect to one inbox, ensure the sending addresses themselves are valid and don't bounce.
Expert view
Expert from Email Geeks says separating mail streams like marketing and transactional is a common and often beneficial practice, which typically does not cause deliverability issues.
2019-05-31 - Email Geeks
Marketer view
Marketer from Email Geeks says it is best not to change sending practices unnecessarily and to maintain coherence and consistency in email sending.
