Comparison

AddSync AI vs Microsoft Copilot

Both help people work with email and calendars. They are built for different setups. Here is an honest look at where each one fits.

The short answer

Copilot is the natural choice when every mailbox is in Microsoft 365. AddSync AI is for companies with Exchange Server on site, mixed systems, or a wish to use Claude or ChatGPT under their own rules.

Side by side

What matters most for a company mailbox.

AddSync AI
Microsoft 365 Copilot
Mailbox location
Exchange Server on site, Microsoft 365, Gmail, Outlook.com and HCL Domino
Mailbox must be in Exchange Online. Microsoft says Copilot has no access to on-premises mailboxes
AI you use
Claude or ChatGPT, or AddSync chat
Microsoft Copilot
Who sets the rules
IT, with data filters and a guard that checks every request
Microsoft 365 permissions and admin settings
Actions
Search, show, save a draft, propose. It cannot send, delete or move mail. People approve
Works inside Outlook and other Microsoft 365 apps
Record of use
A journal of who asked, when and which button. It does not store message text
Depends on your Microsoft 365 auditing setup
Licences
Per account
Microsoft 365 licence plus a Copilot licence per user
Best for
Mixed or on-premises environments, and teams that want to choose their AI
Companies fully inside Microsoft 365

Vendor products change. The statements about other products are based on their public documentation in October 2026, so check the current terms before you decide.

Where Copilot is the better choice

If all your people work in Microsoft 365, use Outlook, Word, Teams and Excel every day and want one assistant across all of them, Copilot is built for that. It lives inside the apps. AddSync AI does not try to replace that.

Where AddSync AI fits

Many companies are not fully in the cloud. They run Exchange Server on site, use Gmail for some teams, or keep HCL Domino. Others want to let people use Claude or ChatGPT but need IT to decide what the AI may see.

  • Your mailboxes are on Exchange Server and cannot be moved yet.
  • You use more than one mail system.
  • You want a guard, filters and a journal that you control.
  • You prefer licences per account, not per product bundle.

You can also use both: Copilot for people who are in Microsoft 365, and AddSync AI for the rest.

Questions

Does Microsoft Copilot work with on-premises Exchange?

According to Microsoft, Copilot is cloud based and has no access to on-premises mailboxes. The mailbox has to be in Exchange Online. Read the full explanation on our on-premises Exchange page.

Can I use AddSync AI and Copilot together?

Yes. They do not conflict. Some people can use Copilot in Microsoft 365, while others on Exchange Server or Gmail use AddSync AI.

Can AddSync AI send emails for me?

No. It can search, show, save a draft and propose. Sending is done by the person.

Which one is cheaper?

It depends on your numbers. AddSync AI is licensed per account, Copilot needs a Microsoft 365 licence and a Copilot licence per user. See our pricing and compare with your Microsoft quote.

Does AddSync AI work in Microsoft 365 too?

Yes. Microsoft 365 is one of the supported systems, next to Exchange Server, Gmail, Outlook.com and HCL Domino.

Try it on your own mailbox

A 14-day pilot with a few mailboxes shows more than any comparison.