Author: Saul

A DMARC aggregate report is a daily XML summary from each mailbox provider showing who sent mail as your domain and whether it aligned. Here is how to read one and what to fix.

A step-by-step procedure for email list cleaning: what to suppress first, how to read verification results, when to sunset inactive subscribers, and how to protect product email.

Published average email open rates range from about 21% to 43%. Here is what each benchmark measured, why they disagree, and what to compare your own numbers against.

Published send-time studies point to weekday mornings, but they disagree on day, hour and metric. Here is what five of them found, why open data misleads, and how to test your own list.

An email drip campaign is a pre-written series of emails sent on a schedule after a starting event. This guide gives six copyable SaaS drip schedules, timing rules, stop conditions and setup steps.

SMTP authentication (SMTP AUTH) makes a client prove who it is before a server accepts its mail. Here is how the exchange works, which mechanism to pick, how to enable it in Postfix, and what the error codes mean.

Which free SMTP server is worth using? We checked each provider’s own pricing page in October 2026 and compare real limits, SMTP relay support and the catches.

A DMARC policy not enabled warning means your domain has no DMARC record or one set to p=none. Here is what each variant of the message means and the exact record that clears it.

Twelve product notification emails with a subject line, example copy and send rules for each, plus how to avoid notification fatigue and classify notifications under CAN-SPAM.

Gmail sending limits from Google’s own docs: 500 emails a day on personal accounts, 2,000 messages on Google Workspace, plus SMTP, relay and API limits.

A command-line SMTP test, step by step: check the port, run a full session with OpenSSL, script it with swaks, probe for open relay, and read every reply code.

An email blacklist is a DNS-based list of IPs and domains that receiving servers use to reject or filter mail. Here is how to check yours with dig or a checker, get removed, and stay off.