Here are important steps to take for domains sending email over mailbaby
1. SPF Configuration
Ensure your SPF record is properly set up and includes the originating IP address of your sending server for domains as well as the server hostname if any emails will come from the server hostname. Many times form emails may include [email protected], and missing spf on the server hostname will prevent those emails from going through.
Misconfigured SPF records can cause legitimate mail to fail authentication and increase the likelihood of delivery issues.
2. Email Forwarding & SRS (Sender Rewriting Scheme)
When using email forwarding, always enable SRS rewriting. Without SRS, forwarded messages may fail SPF and end up in junk/spam folders.
Ensure that SRS-rewritten messages are not manually marked as spam at remote email providers. Instead, use improved filtering rules on forwarded mail to block unwanted messages on your inbound email account.
Keep in mind:
SRS messages tagged as spam often appear as if they are coming directly from Mailbaby IPs.
Mailbaby monitors complaints via feedback loops (Outlook, Yahoo, ReturnPath, and direct reports).
Domains generating excessive spam/junk reports from SRS traffic will have stricter SRS filtering applied.
3. Contact & Signup Forms
Protect all contact and signup forms with bot/spam prevention (e.g., CAPTCHA, hCaptcha, reCAPTCHA).
Forms are common targets for spam runs, open-relay-style abuse, and mail bombing attempts.
Isolate sender addresses:
Avoid sending form submissions directly from the same address you use for real communication (e.g., [email protected]).
Instead, send from a dedicated system address (e.g., [email protected]) and set the reply-to header to the intended inbox (e.g., [email protected]).
This separation prevents reputation issues if spammers abuse your forms.
4. DKIM (DomainKeys Identified Mail)
If your hosting control panel supports DKIM (cPanel, DirectAdmin, Webuzo, Plesk, etc.), enable it.
DKIM improves message authentication, reduces spoofing risks, and significantly improves delivery rates.
5. Bounce-Back Messages & Troubleshooting
Review bounce-back messages carefully—they often contain clues about why an email was blocked.
Common error indicators:
COMPROMISED / LOCAL_BL_FROM → Possible SMTP account compromise detected.
SPF FAILURE → SPF record misconfigured or missing.
Other rule codes → Review against Mailbaby’s security and filtering policies.
6. Use auto responders sparingly
Auto responders are not recommended due to back scatter they may generate. When running an auto responder, it is best to only use it temporarily such as a vacation message. This may not always be possible such as with ticket systems. In these cases inbound email should have a strong spam filter and reject SPF/DKIM/DMARC failures which will prevent potential complaints from mis-directed auto-responders.
7. Set proper reverse dns on your server hostname
While uncommon, some mail servers do deep inspection of recieved headers. Your hand off server may be checked for valid RDNS at some locations. Set this to match your server hostname. Cpanel/WHM systems can use WHM -> email deliverability to set RDNS, DKIM, SPF and DMARC on the server hostname. While generally not required getting these steps will never hurt, and may help on some edge cases.
✅ By following these best practices, you’ll:
Improve deliverability
Reduce spam/junk tagging
Protect your sending reputation
Detect and fix issues quickly
