Open main menu
SOS I Land in SPAM

Email Deliverability, DNS & Email Authentication Guides

Learn how to improve email deliverability, fix spam issues, configure SPF, DKIM, DMARC, and analyze DNS, SMTP, and blacklist problems.

Featured posts

SPF, DKIM and DMARC: The Complete Guide to Email Authentication (2026)SPF, DKIM and DMARC: The Complete Guide to Email Authentication (2026)
Thami Benjelloun

/

SPF, DKIM and DMARC: The Complete Guide to Email Authentication (2026)

A complete guide to SPF, DKIM and DMARC: what they are, how they work, how to configure them, and how to improve email authentication and inbox placement.

DKIMSPFDMARCEmail Deliverability
Why Emails Go to Spam: Causes, Fixes and Deliverability GuideWhy Emails Go to Spam: Causes, Fixes and Deliverability Guide

Why Emails Go to Spam: Causes, Fixes and Deliverability Guide

Emails can go to spam because of authentication issues, poor sender reputation, DNS mistakes, blacklist listings, or weak engagement. This guide explains the main causes and how to fix them.

Email DeliverabilityBest Practices

All posts

Open tag filtersView Tags
DMARC Record Example: Policies, Tags and RolloutDMARC Record Example: Policies, Tags and Rollout

DMARC Record Example: Policies, Tags and Rollout

DMARC record example for none, quarantine and reject policies, with every tag explained, a staged rollout plan and how to verify each record.

Hostinger SMTP Settings: Ports, Login and FixesHostinger SMTP Settings: Ports, Login and Fixes

Hostinger SMTP Settings: Ports, Login and Fixes

Hostinger SMTP settings: smtp.hostinger.com, port 465 with SSL or 587 with STARTTLS, full mailbox username, and how to test them free with mailX.

Zoho SMTP Settings for 2026: Hosts, Ports and FixesZoho SMTP Settings for 2026: Hosts, Ports and Fixes

Zoho SMTP Settings for 2026: Hosts, Ports and Fixes

Zoho SMTP settings: smtp.zoho.com on ports 465 and 587, IMAP on port 993, regional hosts, and fixes for common connection errors.

iCloud IMAP Settings: Server, Port and App Password GuideiCloud IMAP Settings: Server, Port and App Password Guide

iCloud IMAP Settings: Server, Port and App Password Guide

Exact iCloud IMAP settings for Apple Mail and other clients: imap.mail.me.com port 993 SSL, smtp.mail.me.com port 587 STARTTLS, and how to verify them.

SendGrid SPF Record: When to Add the IncludeSendGrid SPF Record: When to Add the Include

SendGrid SPF Record: When to Add the Include

Learn when a sendgrid spf record needs include:sendgrid.net, which DNS records to publish, how to avoid lookup errors and how to verify with mailX.

SMTP Port 25 Blocked: How to Test and Fix ItSMTP Port 25 Blocked: How to Test and Fix It

SMTP Port 25 Blocked: How to Test and Fix It

SMTP port 25 blocked? Test the connection with dig, nc and openssl, then switch to port 587 or 465 with TLS. Step-by-step fixes for ISPs and clouds.

Yahoo IMAP Settings for Mail Clients in 2026Yahoo IMAP Settings for Mail Clients in 2026

Yahoo IMAP Settings for Mail Clients in 2026

Yahoo IMAP settings: imap.mail.yahoo.com port 993 SSL, SMTP on 465 or 587, full-address login, app passwords, and connection checks.

Amazon SES DKIM Setup with DNS RecordsAmazon SES DKIM Setup with DNS Records

Amazon SES DKIM Setup with DNS Records

Configure Amazon SES DKIM using three Easy DKIM CNAMEs, confirm status, and fix pending DNS, proxy, and region issues.

AOL IMAP Settings: Server, Port and SSL Setup GuideAOL IMAP Settings: Server, Port and SSL Setup Guide

AOL IMAP Settings: Server, Port and SSL Setup Guide

Find AOL IMAP settings for Outlook, Apple Mail and Thunderbird: imap.aol.com port 993 (SSL/TLS), smtp.aol.com port 465, and app password steps.

IMAP Port: 993 vs 143 and What to ChooseIMAP Port: 993 vs 143 and What to Choose

IMAP Port: 993 vs 143 and What to Choose

Use IMAP port 993 with SSL/TLS by default, or port 143 with STARTTLS. See provider hosts, mismatch errors, and how to verify the connection.