TL;DR
No provider can guarantee zero spam or zero false positives—spammers constantly adapt and email is an open, global system.
HostBible’s default policy uses a shared collection of filtering rules applied across our platform.
If you need stronger, dedicated filtering, SpamExperts is available as an optional paid add‑on (not included by default).
You can meaningfully cut spam by publishing SPF/DKIM/DMARC, disabling catch‑all mailboxes, tuning thresholds, and maintaining block/allow lists.
Why perfect spam filtering is (almost) impossible
Adversaries evolve daily
Spammers mutate content, rotate domains/IPs, and mimic real brands. Rules that worked yesterday get bypassed tomorrow.Open standards + human email
Email is designed for interoperability. Legitimate messages can look “spammy” (marketing, bulk notices, password resets), while malicious mail can look clean. Filters must balance false positives (blocking real mail) vs false negatives (letting spam through).Look‑alike and newly registered domains
New or compromised domains/IPs often have little reputation history, making early detection hard without risking over‑blocking.Graymail ≠ spam
Newsletters and promotional mail you once opted into aren’t technically spam, but they still feel like it. Filters avoid over‑aggressively blocking these.Language & obfuscation
Multilingual content, image‑only messages, and text obfuscation (special characters, spacing, attachments) dilute the effectiveness of purely content‑based filters.
What HostBible does by default
Shared rule set (platform‑wide):
Our standard incoming mail protection uses a shared collection of filtering rules that combine reputation checks, header analysis, and content heuristics. This balanced policy aims to reduce spam without causing unacceptable false positives across all customers on the platform.Why “shared” matters:
Because this policy serves many domains, we intentionally avoid extremes that could disrupt legitimate mail for others. If you require stricter, domain‑specific controls, see SpamExperts below.
Optional: SpamExperts (paid add‑on)
What it is: A dedicated, enterprise‑grade filtering solution offering deeper controls, quarantines, reporting, and more aggressive detection tuned to your domain.
Availability: Not included by default; it’s available for purchase.
How to add it: Contact HostBible Support and ask to enable SpamExperts filtering for your domain(s).
Steps you (and your team) can take right now
Strengthen your domain’s sender identity
Publish SPF (authorize your sending hosts).
Enable DKIM (cryptographic signing of your mail).
Enforce DMARC with alignment (start with
p=none, monitor, then move toquarantine/rejectas your legitimate sources are aligned).
Result: receivers trust your legitimate mail more and are better at spotting spoofs of your domain.
Reduce exposure and obvious entry points
Disable catch‑all mailboxes. They invite spam by accepting anything@yourdomain.
Use role addresses sparingly (e.g., info@, sales@) and protect publicly listed emails (consider forms over “mailto:” links).
Harden web forms with CAPTCHA/honeypots and server‑side validation to block bot submissions.
Tune what gets through to users
Adjust filtering thresholds (where available in your mailbox or control panel) to be stricter/looser based on your tolerance for false positives.
Maintain allow/deny lists:
Allow known‑good senders or partners.
Block persistently abusive senders, TLDs, or IP ranges (with care—over‑blocking can hide real mail).
Day‑to‑day hygiene
Review spam/junk and quarantine regularly; release/mark “Not Spam” for false positives to help training.
Unsubscribe from legitimate newsletters you no longer want (use the built‑in mail client “Unsubscribe” where safe).
Secure accounts: unique passwords, 2FA where supported. Compromised mailboxes generate spam and get your domain blocklisted.
Educate your users: teach them to spot phishing, look‑alike domains, and suspicious attachments/links.
When should you consider SpamExperts?
You handle mission‑critical mail where false negatives carry high risk.
Your domain is targeted (industry/regulatory profile, high‑value staff).
You need granular quarantine/reporting, domain‑specific tuning, or advanced policies beyond the shared defaults.
If any of the above resonate, reach out to HostBible Support to add SpamExperts to your domain(s).
Troubleshooting quick guide
Too much spam getting through?
Disable catch‑all → 2) Increase sensitivity → 3) Add deny rules for repeat offenders → 4) Verify SPF/DKIM/DMARC → 5) Consider SpamExperts.
Legitimate mail being blocked?
Check spam/junk/quarantine → 2) Add sender/domain to allow list → 3) Reduce sensitivity slightly → 4) Ensure the sender is passing SPF/DKIM and aligns with DMARC.
FAQ
Can HostBible just “turn it up to 11” on the default filter?
Not globally. Our default policy is shared to protect all customers. Aggressive changes can cause widespread false positives. For stricter, domain‑specific control, use SpamExperts.
Is SpamExperts included?
No. SpamExperts is available for purchase as an optional add‑on.
Will SPF/DKIM/DMARC stop all spam?
No, but they significantly improve trust for your legitimate mail and make spoofing your domain harder, which reduces certain classes of spam/phishing.
Need help?
If you’d like us to review your current setup, or to add SpamExperts, contact HostBible Support with your domain name(s) and affected mailboxes.