How do email aliases with different domains affect email deliverability and domain reputation?

Email marketer from Mailjet shares that if an email alias uses a different domain, it is crucial to authenticate emails using both the primary domain and the alias domain. This includes setting up SPF, DKIM, and DMARC records for both domains to maintain a good sender reputation.

Email marketer from StackOverflow shares that DMARC policies need to be correctly configured for all domains, including aliases. A strict DMARC policy on an alias domain can prevent spoofing but also block legitimate emails if not set up properly.

Marketer from Email Geeks answers if the email is sent from DomainA but aliases to DomainB, it's unlikely the Mailbox Provider would know DomainB, as the aliasing happens within DomainA's server, unless there's a CNAME on DomainA's MX record pointing to DomainB.

Email marketer from Email Marketing Forum explains that it is important to monitor the sender reputation of each domain alias separately to ensure that one alias doesn't negatively affect the others. Use tools to track reputation and address issues promptly.

Email marketer from Gmass shares that each domain/email needs to have it's own health tracked as using multiple aliases will only impact this further and may impact deliverability.

Email marketer from Reddit explains that using an alias with a low-reputation domain will negatively impact deliverability, potentially causing emails from your primary domain to land in spam folders.

Email marketer from Neil Patel Digital explains that using an email alias with a different domain can affect your domain reputation. If the alias domain has a poor reputation, it could negatively impact your primary domain's deliverability.

Email marketer from SendPulse answers that using different domain aliases can dilute your sender score if not properly authenticated. It's recommended to align your domain's authentication protocols (SPF, DKIM, DMARC) across all aliases.

Expert from Word to the Wise explains that domain reputation of aliases matters and needs to be monitored. If the alias isn't configured properly it may harm your sending reputation.

Expert from Spam Resource explains that subdomains can be used effectively if managed carefully, but each subdomain needs its own reputation. Using too many subdomains, or not monitoring their individual reputations, can negatively impact deliverability.

Expert from Email Geeks shares that inbox placement is a black box. The best advice is to be consistent with your sending practices, changing them infrequently, so filters can assign the correct reputation.

Expert from Email Geeks explains that every domain in an email has a reputation and the mix of SPF, DKIM, and From domain also has a reputation.

Documentation from Microsoft Learn explains that when sending emails from aliases with different domains, it's important to monitor the sender reputation of each domain. A poor reputation on one domain can affect the deliverability of emails sent from other domains associated with your organization.

Documentation from RFC-Editor responds that SMTP standards require proper domain verification for all sending domains, including aliases. Ensure each alias domain is correctly configured to pass SPF and DKIM checks to avoid delivery issues.

Documentation from Google Workspace Admin Help responds that when using email aliases with different domains, ensure your SPF record includes both domains. This helps receiving servers verify that emails sent from the alias domain are authorized by your primary domain.

Documentation from AWS explains each domain used for sending MUST have valid SPF/DKIM/DMARC or your emails will not get delivered.