HOWTO Improve Email Deliverability with your c Panel

HOW-TO: Improve Email Deliverability with your c. Panel Server by Kevin A. Mc. Grail aka KAM

Introduction

Kevin A. Mc. Grail aka KAM linkedin. com/in/kmcgrail

My Oddest Resume Entry

Some Definitions

What is Spam? CAN-SPAM and similar laws don’t matter. “Bulk” Status doesn’t matter. GDPR doesn’t matter.

What is Spam? “Consent vs Content” Chris Santerre

What is Spam? #1 Source of Cursing #1 Support Ticket #1 Security Vector

What is Not Spam? Transactional emails are an Automatic form of Consent. They are NOT Spam.

What is Apache Spam. Assassin? A Scoring Framework An API & a Program Used by c. Panel

Some SMTP & Spam Basics Response Codes: 2 xx/4 xx/5 xx Greylisting Pros & Cons SMTP Greet Pause & Ratware

Acronyms to Know FPs – False Positives FNs – False Negatives RBL – Realtime Block. Lists

Un. PC Terms to Know Whitelisting Blacklisting Ham/Yam

What is Email Deliverability Getting to the Inbox Reliability “Fire and Forget”

Quiz Break

How to improve Email Deliverability Step 1 Use Static IPs Use Fully Qualified Reverse Pointers (r. PTRs) Policies & Guidelines: https: //postmaster. aol. com/ & https: //gmail. com/postmaster/

SPF Records Step 2 Setup SPF (openspf. org) Try and get to a “-all”. DO NOT USE +all or ? all. Use Includes include: raptor. pccc. com is short for “v=spf 1 ip 4: 69. 171. 29. 0/25 ip 6: 2604: 9100: 7: 9: : /64 ip 4: 38. 124. 232. 0/24 ip 6: 2001: 550: 2 A 00: 1: : /64 -all” Lots of tools to help but none of them will magically know your network setup.

DKIM & DMARC Step 3 Setup DKIM https: //documentation. cpanel. net/display/68 Docs/ Authentication Setup DMARC Dmarcian. com

Troubleshooting Tips Review Mail Logs Review Email Headers Email Culpability

Troubleshooting Tips MXTool. Box (monitoring, checking config, blacklisted) cpanelloop@pccc. com

No, hits=-16. 7 required=5. 8 tests=ENV_AND_HDR_SPF_MATCH, HTML_MESSAGE, KAM_RPTR_PASSED, RCVD_IN_DNSWL_HI, RCVD_IN_HOSTKARMA_W, SPF_PASS, TXREP, USER_IN_DEF_SPF_WL cpanelloop@pccc. com >_ No, hits=-16. 7 required=5. 8 tests=ENV_AND_HDR_SPF_MATCH, HTML_MESSAGE, KAM_RPTR_PASSED, RCVD_IN_DNSWL_HI, RCVD_IN_HOSTKARMA_W, SPF_PASS, TXREP, USER_IN_DEF_SPF_WL No, hits=-1. 1 required=5. 8 tests=DKIM_SIGNED, DKIM_VALID_AU, DKIM_VALID_EF, HTML_MESSAGE, KAM_NUMSUBJECT, KAM_RPTR_PASSED, MIME_HTML_MOSTLY, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H 2, SPF_PASS, TXREP

RBLs and Beyond What is an RBL & How to Add More URIBL/SURBL/Invaluement Free for Some / Disable Rbldnsd Zeta. Scan Using Redis (No More DNS Kludges)

How to improve email deliverability Centralize your outbound SMTP using Smarthosts https: //documentation. cpanel. net/display/68 Docs/Exim+Confi guration+Manager Pros: Easier to Manage & Track Issues Cons: Might not support DKIM out of the box! One spammer / compromised box can cause issues for all

Stay Off Blacklists Stay off real-time blacklists Consider your customer base carefully Monitor things with https: //mxtoolbox. com/

Feedback Loops AOL Postmaster Feedback: https: //postmaster. aol. com/fbl-request JMRP/Hotmail/live/msn/microsoft: https: //mail. live. com/mail/services. aspx https: //sendersupport. olc. protection. outlook. com/pm/Services. aspx Yahoo Complaint Feedback Loop: https: //help. yahoo. com/kb/SLN 3438. html Gmail Postmaster Tools: (Their feedback loop requires MAAWG membership) https: //gmail. com/postmaster/ Return Path: (Comcast, Cox, Rackspace and several other ISPs use them - 18 in total) https: //fbl. returnpath. net/ Even More: https: //sendgrid. com/blog/email-feedback-loops-101/ Mailing lists are #1 cause of false reports

Next Steps ARC shows Promise https: //www. dmarcanalyzer. com/arc-is -here/ Brand Indicators for Message Identification (BIMI) http: //www. brandindicators. org/

Story Break & Tweaks

Apache Spam. Assassin tweaks for c. Panel Latest KAM, deadweight & heavyweight 40% increase in performance with a negligible impact on effectiveness Use your own DNS server. Do NOT use 8. 8!

Write Your Own Rules Meta Rules cause the least FPs Regular Expressions Test your Syntax: spamassassin --lint

Write Your Own Rules only affect YOUR installation! Think about Custom Rules for your Firm Pfizer Story

Example Meta Rule >_ #HEART ATTACK SPAM body __KAM_HEARTPROD 1 body __KAM_HEARTPROD 2 header __KAM_HEARTPROD 3 header __KAM_HEARTPROD 4 /heart ? attack/i /enzyme/i Subject =~ /heart attack|healthy. {4, 10}cells/i From =~ /clear 7/i meta KAM_HEARTPROD (__KAM_HEARTPROD 1 + __KAM_HEARTPROD 2 + __KAM_HEARTPROD 3 + __KAM_HEARTPROD 4 >= 4) describe KAM_HEARTPROD Snake Oil Heart Health du Jour score KAM_HEARTPROD 7. 0

Writing Rules https: //wiki. apache. org/spamassassin/Writing. Rules

c. Panel Specific Gotchas >_ #Add More RAM free –h #Make sure you have spare children ready to go cat /etc/cpspamd. conf maxspare=1 maxchildren=3 #Disable the dormant services for spamd WHM > Server Configuration > Tweak Settings > Dormant Services

Live Ninja Exercise (Time Permitting)

Or, without the app: http: //events. bizzabo. com/polls/011731

Image Credits: KAM - Photo by Ted King Cow - Keith Weller/USDA Apache Spam. Assassin Logo – Apache. org Voodoo Doll - https: //pixabay. com/en/doll-voodoo-magic-1264034/ NOTE: VT Logo & BIMI images used under fair use guidelines.