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 and Yahoo one-click unsubscribe requirements: who must comply, the RFC 8058 header pair, DKIM coverage, the POST, deadlines, and how to validate.
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 do you 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
What is an email alias and how do I set one up?
An email alias is an extra address linked to your main account, so mail to it lands in the same inbox. You set one up in your provider or domain settings.
Jun 6, 2025
What does BCC mean in email?
BCC means blind carbon copy. Recipients in BCC get the message but stay hidden from everyone else on it, which is how you avoid exposing an address list.
Jun 5, 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 is an MUA? Mail User Agents Explained Simply
An MUA is a mail user agent, the email client you read and write in. It sends over SMTP, fetches over IMAP or POP, and renders the messages you receive.
May 13, 2025
What is ARC and how does Authenticated Received Chain preserve authentication?
ARC (Authenticated Received Chain) is an email protocol that preserves SPF, DKIM, and DMARC results through forwarders and mailing lists via signed seals.
May 13, 2025
What is a RUA? DMARC Aggregate Reports Explained
A RUA is the address in a DMARC record's rua tag where receivers send daily aggregate reports: what they contain, why they arrive, and how to stop them.
May 12, 2025