Email News
Browse Palisade articles and guides in Email News.
Analyze email headers online
Analyze email headers online by separating message evidence from DNS and MX checks, then use the right source for routing and transport issues.
Aug 13, 2026
Email reverse DNS best practices
Email reverse DNS best practices: set a PTR for every sending IP, confirm forward DNS, match EHLO, and recheck after IP changes for production senders.
Aug 13, 2026
Email reverse DNS lookup: check and interpret a PTR record
Email reverse DNS lookup: check an SMTP sending IP's PTR record, confirm forward DNS, interpret results, and retest the mail path for reliable mail.
Aug 13, 2026
Google and Yahoo one-click unsubscribe requirements
Google Yahoo one-click unsubscribe requirements differ on sender thresholds, dates, message scope, processing time, and enforcement consequences.
Aug 13, 2026
How does reverse DNS work for email?
How does reverse DNS work for email? Learn how PTR records map sending IP addresses to hostnames, and how forward confirmation works for email delivery.
Aug 13, 2026
Reverse DNS lookup email validation
Reverse DNS lookup email validation checks whether an IP address has a PTR hostname. Learn what PTR results show and what they cannot validate.
Aug 13, 2026
SMTP and POP3 difference: sending versus retrieving email
SMTP and POP3 difference: SMTP sends and relays email, while POP3 retrieves messages from a server to a client mailbox.
Aug 13, 2026
SMTP header analyzer
SMTP header analyzer workflow: paste raw email headers, interpret delivery, SPF, DKIM, and DMARC evidence, then retest the right layer today.
Aug 13, 2026
Braze one-click unsubscribe
Braze one-click unsubscribe requirements need current Braze, RFC, and mailbox-provider documentation before implementation guidance is safe.
Aug 13, 2026
What is spam email and how to prevent it
Spam email is unwanted bulk email that can carry scams or malware. Learn how filters, reporting, and email authentication help prevent it safely.
Aug 12, 2026
What is an IP address? IPv4 vs IPv6 explained simply
What is an IP address? Learn how IPv4 and IPv6 identify network destinations, how DNS uses them, and what they mean for email sending online.
Aug 11, 2026
SMTP vs IMAP vs POP3: what's the difference?
SMTP vs IMAP vs POP3: SMTP sends mail, while IMAP syncs server mail and POP3 downloads it. Learn the secure ports and validation steps clearly.
Aug 11, 2026
A record vs AAAA record: what's the difference?
A record vs AAAA record: A records return IPv4 addresses, while AAAA records return IPv6 addresses. Learn when to publish each DNS record type.
Aug 11, 2026
Difference between IMAP and SMTP
IMAP retrieves and manages mail stored on a server; SMTP transfers and submits outgoing mail between systems, per RFC 9051, RFC 5321, and RFC 6409.
Aug 11, 2026
What is email filtering and how does it prevent spam?
Email filtering evaluates messages for spam and threats using authentication, reputation, and message signals before delivery or quarantine.
Aug 11, 2026
How to configure SPF and DKIM for Chargebee
Configure SPF and DKIM for Chargebee by authenticating the custom SMTP provider, connecting it in Chargebee, and validating a real notification.
Aug 10, 2026
What are this month's product updates MSPs need to know?
Monthly rundown for MSPs: Palisade rolled out AI email scanning, custom subdomains, a dynamic detection workflow, and a clearer security score.
Oct 3, 2025
What Were the Key Email Security Highlights in October 2021?
Cybersecurity Awareness Month, launched by the U.S. Department of Homeland Security, runs every October to promote best practices in digital safety.
Sep 29, 2025
Why Should MSPs Prioritize Email Security?
Companies around the globe rely on managed service providers (MSPs) to keep their IT environments running smoothly.
Sep 29, 2025
What is TLS? Transport Layer Security Explained
Learn how TLS protects your data with encryption, authentication, and integrity checks.
Jun 13, 2025
What is an email Alias? Uses, Setup and Security
Discover what an email alias is and how it organizes your inbox.
Jun 6, 2025
What does BCC mean in email?
Learn what BCC means in email and how it protects privacy.
Jun 5, 2025
What is POP3? Post Office Protocol 3 Explained
Learn how POP3 downloads emails for offline use and local storage.
Jun 5, 2025
What is IMAP? Internet Message Access Protocol Basics
Learn how IMAP syncs emails across devices with server-based access.
Jun 5, 2025
Fix '550 5.1.1' Bounce: Recipient Address Not Found
The 550 5.1.1 bounce means the recipient address failed lookup. Fix typos, stale contacts, and directory sync issues — and stop the NDRs.
Jun 4, 2025
Fix 550 5.4.1 Recipient Address Rejected in Microsoft 365
Fix Microsoft 550 5.4.1 Recipient address rejected: verify the mailbox or alias, Exchange accepted domain, DBEB configuration, hybrid sync, and migration state.
Jun 3, 2025
What are 550 Errors? SMTP Bounce Codes Explained
Explore 550 errors, their many variants, and fixes to boost your email deliverability.
Jun 3, 2025
What is an A record? DNS Address Records Explained
Discover what A records are, how they function, and their role in web and email.
May 29, 2025
What is an MUA? Mail User Agents Explained Simply
Discover MUAs, email clients for sending and managing emails with SMTP, IMAP, and security.
May 13, 2025
What is ARC? Authenticated Received Chain Explained
Learn about ARC, the email protocol preserving SPF/DKIM/DMARC through relays for secure delivery.
May 13, 2025
What is a RUA? DMARC Aggregate Reports Explained
Learn about RUA in DMARC, the URI for receiving aggregate email reports. Discover how it helps monitor authentication and combat spoofing.
May 12, 2025
What is an MTA? Mail Transfer Agents Explained
What is an MTA? Learn how a mail transfer agent sends, receives, routes, queues, and relays email between mail servers using SMTP and DNS.
May 12, 2025
What is SMTP? Simple Mail Transfer Protocol Explained
Discover SMTP, the protocol for sending emails. Learn how it works, its benefits, and tips for secure setup with SPF, DKIM, and DMARC.
May 12, 2025
What is DKIM? DomainKeys Identified Mail Explained
What DKIM is, how the public/private key signature works, the exact DNS record to publish, current key-length guidance, and how it feeds SPF and DMARC.
Apr 23, 2025
Email Security Threats and Statistics 2025
2025 email threats are rising. Learn how phishing works, what Microsoft's DMARC rules require, and how to check your own domain's authentication.
Apr 22, 2025
Why you need to enforce DMARC in 2025?
In 2024, Google and Yahoo cracked down on DMARC. Poor enforcement means email failures, phishing risks, and compliance fines.
Feb 17, 2025
Email Deployment in 2024: What It Means and How to Do It
Email Deployment Guide
May 2, 2024
Debunking: Email Deliverability is not Set and Forget
Email deliverability hinges on constantly evolving compliance, protocols, and security practices, necessitating frequent updates and monitoring to…
Mar 25, 2024
How to Hit Your Lead's Inbox (Gmail & Yahoo 2024 Update)
Beginning in early 2024, Google and Yahoo are changing their requirements for sending emails.
Nov 21, 2023
How does DNS fix Email Deliverability?
Fix email deliverability at the DNS level: correct SPF, DKIM, DMARC, MX, and PTR records decide whether your mail reaches the inbox.
Aug 9, 2023
How to Understand DMARC Reports
Email delivery is crucial for businesses to communicate effectively with their customers, partners, and employees.
Aug 9, 2023
Why is My Company Logo Not Displaying in Gmail?
Logo not showing in Gmail? Check your BIMI record, SVG format, DMARC enforcement, and VMC — the fixes that get your brand displayed.
Aug 9, 2023
How Companies Get the Verified Blue Checkmark on Twitter
How companies get verified on Twitter/X: eligibility, the application process, and how verification protects your brand from impersonation.
Aug 9, 2023
A Step-by-Step Guide to Getting Verified on Facebook
Getting verified on Facebook can significantly boost your credibility and visibility.
Aug 9, 2023
Meta's Paid Verification for Creators
Paid verification, as the name suggests, involves a fee-based process where users can apply for verification on Instagram.
Aug 9, 2023
Office 365 Quarantine: Protecting Your Organization from Threats
Office 365 quarantine explained: how Microsoft filters suspicious mail, how admins review and release messages, and how to tune your policies.
Aug 9, 2023
How do I get a Blue Gmail Checkmark?
Get the blue Gmail checkmark: set up DMARC enforcement, a BIMI record, and a Verified Mark Certificate so Gmail shows your brand as verified.
Aug 9, 2023
Comprehensive Guide to DNS CNAME Records
A DNS CNAME record aliases one hostname to another. Learn how CNAMEs work, when to use them, the apex-domain rule, and how they power DKIM setup.
Aug 9, 2023
DNS TXT Record Lookup: dig, nslookup & Online Tools
Look up DNS TXT records with dig, nslookup, PowerShell, or our free online checker. Find and interpret SPF, DKIM, DMARC, BIMI, and verification records.
Aug 9, 2023
Top 10 Reasons Why DKIM Fails
Top 10 reasons DKIM fails: wrong selectors, DNS errors, key length, forwarding — and how to fix each so your email passes authentication.
Aug 9, 2023
How to Create an SPF Record (Step-by-Step + Examples)
Build a valid SPF record in minutes: syntax, the 10-lookup limit, real examples for Google Workspace and Microsoft 365, and a checker to verify it.
Aug 9, 2023
How much does it Cost to Trademark a logo?
How much a logo trademark costs: USPTO filing fees, attorney costs, and timelines — plus why a registered logo matters for BIMI email branding.
Aug 9, 2023
How to Prevent ARP Spoofing Attacks
Learn how to detect and prevent ARP Spoofing with practical, effective strategies.
Aug 9, 2023
Introduction to SPF Records
If you're involved in managing email deliverability for your tech company, you may have come across the term 'SPF record.' An SPF record, which stands for…
Aug 9, 2023
Setting Up a DKIM Record for Email Security
Set up a DKIM record step by step: generate a 2048-bit key, publish the DNS TXT record, verify signing, and fix the errors that break DKIM.
Aug 9, 2023
In-Depth Guide to Understanding and Implementing DMARC and DKIM
DKIM, or DomainKeys Identified Mail, is an email authentication method that associates a digital signature with an email message.
Aug 9, 2023
How to Flush DNS Cache on Mac, Windows & Linux
Clear your DNS cache in one command — macOS, every Windows version, and Linux distros — plus how to flush browser DNS and confirm it worked.
Aug 9, 2023
How to Create a BIMI Record: A Step-by-Step Guide
Set up BIMI step by step: enforce DMARC, create an SVG Tiny PS logo, choose a VMC or CMC, publish the TXT record, and troubleshoot display.
Aug 9, 2023
Unmasking the Secrets of IP Spooking
IP spoofing lets attackers fake source addresses to bypass filters and launch attacks. Learn how it works and how to defend your network.
Aug 9, 2023
SMS Spoofing: Understanding and Mitigating Risks
SMS spoofing lets attackers fake sender IDs in text messages. Learn how smishing works and how to protect your business and customers.
Aug 9, 2023
DNS TXT Records Explained: Format, Uses & Examples
What a TXT record is, the exact syntax, and how TXT records power SPF, DKIM, DMARC, and domain verification — with copy-paste examples.
Aug 9, 2023
DMARC Policy Not Enabled: How to Fix It Safely
Fix the 'DMARC policy not enabled' warning: check p=none, verify every legitimate sender, then move to quarantine and reject without disrupting real mail.
Aug 9, 2023
The ABCs of DNS PTR Records
PTR records map your sending IP back to your hostname. Learn how reverse DNS and FCrDNS work, why Gmail and Outlook now enforce them, and how to set one up.
Aug 9, 2023
Protect Yourself from Malicious Email Attachments | Tips & Prevention
Malicious email attachments deliver most malware. Learn the file types to watch, how to verify senders, and defenses that stop infected files.
Aug 9, 2023