The short answer: all three assist with email well and none of them manage it end to end, though the gap is narrower than it was a year ago. Copilot’s Prioritize my inbox now scores arriving mail in the background, Gmail’s AI Inbox drafts replies and surfaces to-dos on top AI plans in the US, and ChatGPT can read your mail through a connector and run a scheduled briefing prompt; what none of them do is act on that triage, keep a reviewable list of sent mail still awaiting a reply, or fold email and calendar into one unprompted report. If labels and on-demand drafting cover your complaints, use what you already pay for and buy nothing. alfred_ ($29.99/month flat) is worth adding only if you want the loop closed, and it is the wrong purchase if Copilot in Outlook already covers what you needed.
The useful test is not which model is smarter. It is whether anything in your inbox is different this morning because of work that happened while you were asleep, and whether that difference is a label or a decision.
Same criteria per row. All four now do something without a prompt. The difference is whether the unprompted work stops at a label or continues into a decision, a draft and a report.
| Option | What it does autonomously | Email + calendar | Price | Best for |
|---|---|---|---|---|
| ChatGPT | Scheduled Tasks run prompts you wrote in advance, such as a daily briefing. Connectors read and search Gmail on request. Agent mode is user-initiated and asks before high-impact actions | Neither natively; connectors read, they do not run your inbox | Free tier; Plus $20/mo; Business $25/user/mo | Writing the hard message, and answering questions about your mail on demand |
| Copilot in Outlook | Prioritize my inbox scores arriving mail high, normal or low as it lands. Summaries, drafts and rewrites are on request. Triage verbs stay manual | Email and calendar, inside Microsoft 365 | Business add-on $21/user/mo yearly, currently $18 promotional; Business Standard with Copilot $23.50/user/mo yearly | Organizations already on M365 who want AI across every Office app |
| Gemini in Gmail | Nudges resurfaces sent mail nobody answered. AI Inbox drafts replies and surfaces to-dos, gated to top AI tiers and the US. Summaries and Help me write are on request | Email and calendar, inside Google Workspace | Bundled into Workspace plans: Starter $7, Standard $14, Plus $22 per user/mo annual | Gmail users who want good help with zero setup and no extra line item |
| Dedicated assistant (alfred_, Fyxer) | Runs unprompted. alfred_ triages and archives noise, drafts replies, tracks unanswered threads, extracts tasks, manages the calendar and sends a Daily Brief. Fyxer sorts inbound mail, categorizes awaiting-reply threads and pre-writes drafts | alfred_ covers both, Gmail and Outlook; Fyxer is email only | alfred_ $29.99/mo or $299.99/yr flat; Fyxer $22.50/mo Starter annual | People who want the inbox worked while they are not looking at it |
Choose Copilot if your company already pays for it and you want AI in Word, Excel and Teams as much as in Outlook, because at that point marginal cost is zero and Prioritize my inbox is a real feature rather than a marketing line. Choose Gemini in Gmail if you live in Gmail on a Workspace plan, since it is bundled and costs you nothing additional to try. Choose ChatGPT if the bottleneck is composing difficult messages, or you want to ask questions about your mail rather than have it handled. Choose a dedicated assistant if the failure you keep having is that things got past you, or that you cannot answer “what am I waiting on” without opening five threads.
What changed, and what did not
The old version of this answer was simple: built-in AI is invoked, assistants run. That line has moved and it is worth being straight about it.
Copilot in Outlook will now review emails as they arrive and assign a priority, in parallel with mail delivery, without you asking. Google has been shipping the same direction in Gmail, with an AI Inbox that goes further and drafts replies and marks to-dos as done, though it is currently restricted to the highest AI subscription tiers and to the United States. ChatGPT’s Scheduled Tasks will run a prompt on a timer, so a daily inbox briefing is technically something you can build there today.
What has not changed is where the work stops.
Nothing acts on the triage. Copilot labels a message high priority. It does not archive the low-priority ones, and the verbs that would actually shrink your inbox stay in your hands as chat commands. A priority label on 150 messages is a better-ordered pile of 150 messages.
Nothing keeps the outbound list. Gmail Nudges will resurface a sent message nobody answered, which is genuinely useful, and Google decides which ones and when. Neither Copilot nor Gemini gives you a complete, reviewable answer to “what am I currently waiting on”, which is the question that costs people deals.
Nothing joins email to the calendar unprompted. A commitment you made in an email does not become a calendar block, and the conflict it creates does not get flagged, unless you go and ask.
The scheduled prompt is not standing management. A ChatGPT task runs the instruction you wrote last month. It has no memory of what it told you yesterday, no notion of a thread it is tracking, and no ability to change its mind about what matters.
What Copilot in Outlook actually covers
Copilot is the strongest of the three on email, because it is the only one that is a first-class citizen inside a mail client with a calendar attached. It will summarize a long thread accurately, draft a reply from thread context, rewrite for tone, catch you up on what you missed, search the mailbox in natural language, and score arriving mail by priority using signals like who is on the thread and their job titles.
Pricing, from Microsoft’s own page: the Microsoft 365 Copilot Business add-on lists at $21 per user per month billed yearly, currently discounted to $18 through 30 September 2026, and requires a qualifying Microsoft 365 licence for up to 300 users. Bundled options include Business Standard with Copilot at $23.50 per user per month yearly.
Two limits worth knowing before you assume it has you covered. Prioritize my inbox only scores mail that arrives after you turn it on, so it does nothing about the backlog. And Copilot in Outlook requires a Copilot licence; there is no permanent free consumer tier for it.
What a dedicated assistant adds
alfred_ is an AI executive assistant for your email and calendar: it triages your inbox, drafts replies, tracks what needs a response, and manages your calendar. Concretely: it archives noise and flags what needs you across Gmail and Outlook or Microsoft 365, drafts replies in your voice for approval, tracks threads that are waiting on a reply, extracts tasks out of email, handles scheduling, conflicts and reminders on the calendar, and sends a Daily Brief by SMS or email of what needs attention today. Nothing sends without your approval. It connects over OAuth with no password, the company is SOC 2 Type 2, and it is $29.99 a month or $299.99 a year on one flat plan with no tiers and a free trial.
Fyxer AI is the narrower version of the same idea at $22.50 a month on the annual Starter plan ($30 monthly): it sorts inbound mail for Gmail and Outlook, categorizes threads into To Respond, Awaiting Reply and To Follow Up, and leaves suggested drafts including for the follow-ups. If email is the whole problem and calendar is not, it is the cheaper answer and a fair one.
Whether either is worth adding on top of AI you already have comes down to one honest question. In the last quarter, did anything get past you that cost more than a few hundred dollars of time, standing or revenue. If nothing did, the built-in tools are sufficient and this category is a solution to a problem you do not have.
The rule of thumb
The question is not which AI writes the better reply. It is which AI notices the email you never opened, and then does something about it.
A priority label is a better-sorted pile, not a smaller one.
If it only works when you click it, it is a writing tool, not an assistant.
The stacking answer
Nobody has to choose exclusively, and the people who get the most out of this usually do not.
Keep Copilot or Gemini for the invoked work: the hard paragraph, the thread you need summarized, the tone rewrite before you send something consequential. They are already paid for and they are good at it. Turn on the free background features you have, which means Prioritize my inbox on Copilot and Nudges in Gmail, and live with them for a few weeks before spending anything. Add an assistant layer only if the gap is still there afterwards: things getting past you, threads going quiet unnoticed, commitments never reaching the calendar.
Write down every time email fails you over that month. If the entries are all “this took too long to write”, you are done and you should buy nothing. If the entries are “I did not see this” or “I never chased that”, read our best AI email assistant test next, and if you are on Microsoft 365 specifically, the Outlook head-to-head goes deeper on the Copilot comparison.