AI email comparison

OpenAI (ChatGPT) vs Grok (xAI) for Email Drafting

You already use AI to draft emails. The question is which tool sounds most like you, and whether there's a better option than either.

Option A

OpenAI (ChatGPT)

The most widely used AI assistant. Most ChatGPT-for-email power users start here, because it's the tool they're already tab-switching to.

Strengths for email

  • Familiar interface; most users already have an account
  • GPT-4o is strong at following complex style instructions
  • Huge prompt-engineering community (r/ChatGPT, YouTube tutorials)
  • Functions well as a catch-all AI for non-email tasks too

Weaknesses for email

  • No persistent memory of your email style across sessions
  • Requires manual copy-paste into Gmail or Outlook every time
  • Generic outputs unless you write elaborate system prompts
  • ChatGPT 'tells' (em-dashes, 'I hope this email finds you well') are widely detectable

Pricing: Free tier available; ChatGPT Plus ~$20/mo

Best for: General AI drafting when you want manual control over every word

Option B

Grok (xAI)

Elon Musk's xAI model. Strong technical capabilities and current events access via X integration. Still maturing for professional email use cases.

Strengths for email

  • Real-time information access via X (Twitter) integration
  • Strong at casual, direct prose
  • Available bundled with X Premium
  • Grok 3 shows significant capability improvements

Weaknesses for email

  • Limited professional email track record vs. OpenAI/Anthropic
  • No Gmail or Outlook integration
  • Community prompt resources thin compared to ChatGPT ecosystem
  • Casual default tone requires heavy instruction for formal email

Pricing: Bundled with X Premium (~$8-16/mo)

Best for: X/Twitter power users who already pay for Premium and want a bundled AI

Head-to-head for email

Criteria
OpenAI (ChatGPT)
Grok (xAI)
Gmail integration
Copy-paste or use a BYOK tool like ForthWrite
Copy-paste or use a BYOK tool like ForthWrite
Outlook integration
Copy-paste or use a BYOK tool like ForthWrite
Copy-paste or use a BYOK tool like ForthWrite
Setup required
API key + model name only
API key + model name only
Data residency
Provider-dependent
Provider-dependent
Learns your voice
No persistent memory
No persistent memory
API pricing
Standard market rate
Standard market rate
Multiple AI providers
One provider
One provider

The problem neither solves

Both OpenAI (ChatGPT) and Grok (xAI) share the same fundamental limitation for email: they start cold every time. They have no memory of how you actually write: your sentence length, your opener patterns, your sign-off habits, the inside-jokes you use with specific clients. You compensate with elaborate system prompts that you re-paste on every session.

The outputs are good, but they're generically good. Recipients increasingly recognize the cadence of AI-drafted email: the em-dash overuse, the "I hope this finds you well," the verbose sign-off. These tells erode trust in relationship-driven communication.

The alternative is a tool that actually learns your sent email history, not from a one-time prompt, but from the real pattern of how you write. ForthWritedoes this inside Gmail and Outlook directly. You don't tab-switch; you draft in your inbox, and the AI knows your voice because it has read your email history.

Stop patching your prompt. Learn your voice once.

Build a first-person persona prompt that captures how you actually write. Free, in under 5 minutes.