The SendHustle blog
Guides and tutorials on email automation, cold outreach, mail merge, and getting more replies.
Page 3 of 4 · 37 articles
5.4.5 Daily User Sending Limit Exceeded: Which Quota You Hit
Google issues two different 5.4.5 bounces. Work out which Gmail or SMTP relay counter you tripped, when the rolling window resets, and what to change.
Gmail Mail Merge Limit: 1,500 a Day, Not Your Full 2,000
Gmail's mail merge caps at 1,500 a day, not 2,000 — and quietly cuts your daily recipient budget from 10,000 to 1,500. Here's the full arithmetic.
DLT Registration for Email India: What TRAI Actually Covers
DLT registration covers SMS, not email. Here is the TRAI definition that settles it, and the two regimes that do govern commercial email to Indian...
Gmail Spam Rate Over 0.3%: How to Find Which Emails Did It
Your Gmail spam rate over 0.3% is a domain-wide average. Here is the arithmetic that isolates which sending stream caused it, before you freeze anything.
Do Transactional Emails Need an Unsubscribe Link? Three Layers
Transactional emails are exempt from CAN-SPAM's opt-out rule — until the primary purpose test reclassifies them. The three layers that decide, explained.
Send Email From Google Sheets Without Apps Script: 4 Routes
Four ways to send email from Google Sheets without Apps Script, and the three different sending quotas each one spends - with Google's real published...
Transactional vs Bulk Email: What's the Difference (and Why Mixing Them Hurts You)
Transactional vs bulk email: the real difference, why mixing them on one domain risks your receipts, and how to separate them with subdomains and DNS.
Cold Email Deliverability: How to Land in the Inbox, Not Spam
You can write the perfect email, but if it lands in spam it never gets read. Here's how authentication, sending pace, list hygiene, and content decide your deliverability — and how to stack the odds.
Mail Merge in Gmail: How It Works — and When to Outgrow It
How mail merge in Gmail actually works, where Gmail's daily limits stop you, and when to switch to sending from your own domain instead.
Follow-Up Sequences That Stop the Moment Someone Replies
Most replies come from the follow-up, not the first email. But nothing burns trust faster than "just bumping this" after someone already answered. Here's how to build sequences that stop themselves.
Personalization at Scale: Merge Tags, Fallbacks, and Spintax
Real personalization is more than {FirstName}. Learn how merge tags, fallback helpers, and spintax let you write one campaign that reads like a thousand individual emails.
How Many Emails Can You Send From Gmail Per Day?
Gmail and Google Workspace cap how many emails you can send per day — and blowing past the limit can get your account throttled or flagged. Here are the real numbers and how to send safely at scale.
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