How to send a client the times your whole team is free

The task

You need three people from your side on a call with someone outside your company. You open the Scheduling Assistant, add your colleagues, and there it is: a grid with everyone's busy blocks and a few suggested times.

Then you try to send it to the client, and you find out the grid does not travel. There is no export. Suggested times cannot be copied out as text. So you read the grid, type "Tuesday 10:00, Wednesday 2:00, Thursday 9:00 or 11:30" into an email, and hope you did not misread a row.

This is one of the oldest unfixed complaints in Outlook. People have been asking Microsoft for a way to produce a multi-day list of combined availability for years, and the answer is still that the data is there but the report is not.

Why the obvious options do not work

Just send the invite. Fine if everyone is inside your tenant. The moment an external guest is involved, you are guessing at their calendar, and a wrongly timed invite costs you a decline and another round trip.

Scheduling Poll. Good when you are happy to have recipients vote, and it handles the booking for you. Less good when you are the vendor and the client expects a straight answer to "when are you free", or when you are proposing times on behalf of an executive who does not want a poll going out under their name.

A booking link. Works when the other side is willing to click through to a page and pick. Sometimes they are not: senior buyers, candidates who are cautious about third-party pages, procurement contacts on locked-down browsers. And a link only shows one person's availability unless you have set up a collective event type.

Share the calendar. External free/busy sharing only works if the two tenants are set up to share it, and you often do not want a client seeing your team's whole week anyway.

Screenshot the grid. Please do not. It is unreadable on a phone and it is wrong in every time zone but yours.

What a good answer looks like in the email

The thing the client actually wants is four or five lines of text they can scan and reply to:

All times Eastern. Happy to work around yours.

• Tue, Sep 22 - 10:00 to 11:30
• Wed, Sep 23 - 14:00 to 16:00
• Thu, Sep 24 - 09:00 to 10:00, 13:30 to 15:00

No login, no click, no page. They reply with a time, you send the invite. Two emails instead of five.

Doing it without the manual read-off

This is what OpenSlot does. In "Me + others" mode you pick the colleagues who need to be on the call, and it merges their Microsoft 365 free/busy into one set of times when all of them are free. You copy the list, or use the Outlook add-in to insert it straight into the email you are already writing.

The controls are the ones that matter for this job:

• Any time zone. Generate the list in the client's zone if that is kinder, and say so in the email.
• Up to 60 days on Pro, seven on the free plan. A two-week window for a sales call; a six-week window for a panel that has to fit around travel.
• Working hours, default 8 to 5, so you are not offering 7 a.m.
• Minimum slot length, so a 20-minute gap between two meetings never gets offered as a meeting slot.
• Weekends on or off.
• Tentative as busy, which matters more with several calendars than with one. Merge four people and a couple of tentative holds will otherwise produce times nobody can actually make.

It reads free/busy only, read-only, through delegated Microsoft Graph scopes. It uses only the availability and stores no calendar data; availability is computed live each time. So the list you send says when your colleagues are free and nothing about what they are doing.

Settings roam across devices, so the window and working hours you set in the web app are the same ones the add-in uses in Outlook on Windows, Mac, and Outlook on the web.

Practical notes for merging calendars

Keep the group small. Three or four people is workable. Add eight and the intersection collapses to nothing. If you need eight, propose two candidate windows and let the client pick, or use a poll.

Check who actually has to be there. Half of "no common time" problems are optional attendees treated as required.

Free/busy has to be visible to you. Colleagues inside your tenant normally are. People in a different tenant are a different problem, and no tool gets around a tenant that does not publish free/busy.

Say the time zone in the email. Every time. It costs one line and saves one round trip.

Offer ranges, not exact starts, when you can. "14:00 to 16:00" gives the client room to choose and makes you look easy to work with.

What it costs

The Free plan covers you plus one other person with a 7-day window, which is enough to test the merge with one colleague. Every new account starts with a 14-day Pro trial, no card. Pro is $7 per user per month or $72 a year. Team starts at $5 per user per month with a five-seat minimum and volume tiers, billed through Stripe, which is the plan that fits a pod of recruiters or an agency team doing this several times a day.

Pick the right tool

If the meeting is internal, book it. If you are fine with recipients voting, Scheduling Poll is free and already in your tenant. If your recipients happily use booking links, use a booking link.

If you are the one emailing clients and candidates several times a day, and what you want is a short list of times in the body of the message, that is the job OpenSlot was built for. The add-in is listed on Microsoft Marketplace, and questions go to support@useopenslot.com or our help pages.