Nobody loves writing emails, but everybody has to. The average office worker spends over two hours a day in their inbox — and most of that time goes into drafting, rewording, and second-guessing tone. AI promised to fix this. Some of it actually does.
We spent two weeks writing real emails with the three most popular AI writing tools — cold outreach, follow-ups, apologies, polite declines — and judged them on one thing: did the email get better, faster?
🥇 Grammarly — best for everyday email polish
Grammarly is the only tool on this list that lives inside your inbox. It watches as you type in Gmail or Outlook and fixes grammar, sharpens sentences, and — the genuinely useful part — flags tone. Writing a frustrated reply at midnight? It will gently suggest you sound less frustrated.
The free version handles basic corrections well. Premium (around $12/month) adds full-sentence rewrites and tone suggestions, which is where the real email value lives. If you write more than ten emails a day, this is the one to get.
Weakness: it polishes what you wrote, but it won't draft an email from scratch the way a chatbot can.
🥈 ChatGPT — best for drafting from nothing
Staring at a blank compose window? ChatGPT is unmatched at turning a messy bullet list into a clean, professional email. Give it 'tell the client the project is delayed two weeks but we added extra features' and you get a draft you can send with light edits.
The free tier is enough for occasional drafting. Plus (around $20/month) is worth it if you also use it for other writing — but for email alone, free is fine.
Weakness: you have to copy-paste between tabs. There is no inbox integration, so it adds friction to every email.
🥉 Claude — best for tricky, sensitive emails
Claude writes the most human-sounding emails of the three. For delicate situations — turning down a vendor, delivering bad news, negotiating — its drafts need the fewest edits and never sound robotic.
The catch is the same as ChatGPT: no email integration, and the Pro plan (around $20/month) is harder to justify for email alone. But if your job involves high-stakes communication, Claude's tone judgment is worth it.
So which should you pick?
It depends on your bottleneck. If you already write the emails and just want them cleaner and faster, get Grammarly — it is always there, inside the inbox, doing the work silently. If blank-page dread is your problem, ChatGPT's free tier drafts anything in seconds. And if you regularly write emails where the wrong tone costs money, Claude is the safest pair of hands.
Our honest stack: Grammarly Premium running in the inbox every day, plus ChatGPT free for the occasional cold draft. Total cost: around $12 a month for an inbox that practically manages itself.