GPT-5.5 vs Qwen3.7 Max for writing emails

The verdict

GPT-5.5 wins, 9893

Same 12 writing emails tasks, marked blind by three rival labs. GPT-5.5 took 4 tasks, Qwen3.7 Max took 1, 7 tied. Tested 14 Aug 2026.

Where they differed most

The task — Chase an unpaid invoice

Write an email chasing invoice #1042, now 21 days overdue, to a long-standing client. Firm but warm, under 110 words, must state the amount is £1,840, must not use the word 'unfortunately', and must end with one specific next step.

GPT-5.510/10
Subject: Invoice #1042 overdue

Hi [Name],

I hope you’re well. I’m following up on invoice #1042 for £1,840, which is now 21 days overdue. We really value our long-standing relationship and would appreciate your help in bringing the account up to date.

If payment has already been made, please disregard this note.

Please arrange payment of £1,840 by Friday 21 August.
Subject: Following up: Invoice #1042

Hi [Name],

I hope you’re having a good week. 

I’m checking in on invoice #1042 for £1,840, which is now 21 days overdue. We truly value our long-standing partnership, so I suspect this simply slipped through the cracks! 

To get this sorted, please process the payment today. If you need me to resend the invoice, just let me know. 

Please reply to this email by 5 PM tomorrow to confirm your payment date.

Best regards,

[Your Name]

Task by task

TaskGPT-5.5Qwen3.7 Max
Chase an unpaid invoice108
Decline a meeting politely1010
Give bad news1010
Introduce two people89
Subject lines that inform108
Reply to an angry email108
Ask for a pay rise meeting1010
Cancel a contract cleanly1010
The one-line email108
Out of office that helps1010
Follow up without nagging1010
Refuse to write it1010

Full receipts: GPT-5.5, Qwen3.7 Max · judges claude-sonnet-5, gemini-3.1-pro-preview, grok-4.5

Questions people ask

Which is better for writing emails: GPT-5.5 or Qwen3.7 Max?

GPT-5.5 — it scored 98/100 against 93/100 on our 12-task writing emails suite, winning 4 tasks to 1 with 7 tied. Every answer was marked blind by three judges from three rival AI labs.

How was this tested?

Both models answered the identical published writing emails tasks. Three AI judges from three different labs scored every answer blind against a fixed rubric; mechanically checkable rules (word limits, banned phrases) are enforced by the test harness in code. The raw outputs and judge verdicts are downloadable.

More writing emails head-to-heads: GPT-5.5 vs GPT-5.6 Sol · GPT-5.6 Sol vs Qwen3.7 Max · GPT-5.3-Codex vs GPT-5.5 · GPT-5.3-Codex vs Qwen3.7 Max · GPT-5.5 vs GPT-5.6 Luna · GPT-5.5 vs GPT-5.6 Terra

Full ranking: Best AI for writing emails · model pages: GPT-5.5, Qwen3.7 Max