Guides tagged “deliverability”
Step-by-step MdmHost guides about deliverability, sorted A-Z.
7 guides
Check and fix reverse DNS (PTR) so your email is not rejected
Find your mail server's sending IP, check its PTR record, make forward and reverse DNS match, and fix the bounces caused by missing rDNS.
Common email bounce errors explained (550, 552, 554, 421) on cPanel
Understand the bounce messages you receive from cPanel mail servers: user unknown, mailbox full, SPF and DMARC failures, blocklists, rate limits and temporary deferrals.
Configure SMTP mail in WHMCS so emails reach the inbox
Switch WHMCS from PHP Mail to SMTP or OAuth (Google, Microsoft 365), choose the right port and encryption, send a test message and fix emails that fail or land in spam.
DMARC on cPanel: read reports and move from p=none to reject
Go beyond a basic DMARC record: receive and read aggregate reports, find who sends mail as your domain, and tighten the policy step by step from none to quarantine and reject.
Fix email deliverability for customer accounts in WHM
Check and repair SPF, DKIM and PTR records for your customers' domains with WHM Email Deliverability, add DMARC, and stop mail landing in spam.
One SPF record for several mail services (and the 10-lookup limit)
Combine cPanel, Google Workspace, Microsoft 365, newsletter and CRM senders into a single valid SPF record, stay under the 10 DNS lookup limit and avoid common SPF errors.
Why your emails go to spam (and how to fix it on cPanel hosting)
A checklist to stop emails from your cPanel domain landing in Gmail or Outlook spam: authentication, From addresses, content, blocklists, PHP mail and warm-up.
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