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BNবাংলা#Email Authentication
Email authentication is the set of DNS-based standards that prove a message really comes from the domain it claims. The core trio is SPF, DKIM and DMARC, supported by related standards such as BIMI, MTA-STS and reverse DNS. Mailbox providers use authentication results as one of the first signals when they decide whether to trust a message. Without it, legitimate mail is more likely to be filtered and criminals can impersonate the domain more easily. The articles under this tag explain how the standards fit together and how to check them.
Sep 16, 2026 · 8 min readDMARC for Subdomains: How the sp Tag Protects Your Domain
Attackers can spoof subdomains you never use. Learn how DMARC applies to subdomains, what the sp tag does, and how to set policies for…
Sep 14, 2026 · 7 min readHow to Authenticate Third-Party Email Senders for Your Domain
CRMs, helpdesks, newsletter and invoicing tools often send as your domain without proper authentication. Learn how to find them and align each with DMARC.
Sep 13, 2026 · 7 min readHow to Test Email Deliverability Before You Hit Send
How to test whether your e-mails will reach the inbox: header checks, seed tests across providers, DNS checks and the limits of each method,…
Sep 11, 2026 · 8 min readDKIM Failing? How to Troubleshoot dkim=fail and dkim=none
A step-by-step guide to fixing DKIM failures: missing keys, wrong selectors, truncated records, modified messages and signatures that use the wrong domain.
Sep 9, 2026 · 7 min readSPF Softfail vs Hardfail: Should You Use ~all or -all?
Should your SPF record end with ~all or -all? Learn what softfail and hardfail do, how receivers treat them with DMARC, and which ending…
Sep 8, 2026 · 8 min readDMARC Alignment Explained: Relaxed vs Strict Mode
DMARC passes only when SPF or DKIM aligns with your From domain. Learn how relaxed and strict alignment differ, and which mode suits your…
Sep 2, 2026 · 8 min readShould You Send Marketing Email from a Subdomain? Pros and Cons
Sending newsletters from a subdomain can protect your main domain's reputation. Learn when it helps, when it does not, and how to authenticate it…
Sep 1, 2026 · 7 min readEmail Deliverability Checklist: 20 Checks for Small Businesses
A practical 20-point e-mail deliverability checklist for small businesses: DNS records, sending systems, list habits and monitoring, in the right order.
Aug 31, 2026 · 7 min readOrder Confirmation Emails Not Arriving? Fix Your Shop’s Mail
Online shop order and shipping e-mails missing or in spam? Learn why transactional mail fails, how to authenticate it and how to separate it…
Aug 29, 2026 · 8 min readSwitching Email Providers: A Checklist to Avoid Lost Mail
Moving business e-mail to a new provider? Follow this checklist for MX, SPF, DKIM, DMARC, TTLs and mailbox migration so no messages are lost…
Aug 28, 2026 · 8 min readHow to Read Email Headers to Check SPF, DKIM and DMARC
E-mail headers show exactly why a message passed or failed authentication. Learn how to open them in Gmail and Outlook and read Authentication-Results.
Aug 27, 2026 · 8 min readEmail Forwarding and Authentication: SPF, SRS and ARC Explained
Forwarded e-mail often fails SPF and sometimes DMARC. Learn why forwarding breaks authentication and how DKIM, SRS and ARC keep forwarded mail deliverable.