We connect business mail with AI, safely
AddSync is built by people who have run company mail and calendar systems for decades. We make AI useful in a mailbox without giving up control of the data.
Why we built AddSync
We run Exchange, and we have watched companies struggle with two problems for years.
First, calendars, contacts and tasks live in different systems and do not agree. People book twice, miss meetings and copy data by hand.
Then AI arrived. Employees want it to read the mailbox, plan the week and draft replies. IT teams, rightly, do not want to hand over mailbox passwords or send everything to a tool they do not control.
AddSync is the answer to both. Sync keeps your systems in step. AddSync AI lets AI work with mail and calendars through a guard, with your rules, your approval and a full journal.
Where we come from
AddSync grows from practical work with company mail, not from a slide deck.
- 1994
IT services for companies
We start by building and running IT for businesses, and we have never stopped.
- 2008
Exchange hosting in the EU
We start host-exchange.com, a hosted Microsoft Exchange service for companies, run on servers in the EU.
- Then
Mail filtering and sync
We add email filtering for companies, and we build the first AddSync tools to keep calendars, contacts and tasks in step.
- 2026
AddSync AI
We bring AI to the mailbox under human control, for Exchange, Microsoft 365, Outlook.com, Gmail and HCL Domino.
How we work
Six rules that guide what we build and how we answer.
People stay in control
AI proposes, people approve. A journal shows what was done, so nothing happens in the dark.
Least access
We ask for the permissions a task needs and no more. For Exchange there is a service user, so no one shares mailbox passwords.
Your data stays yours
We do not sell it and we do not train AI models on your mailbox or calendar.
Works with what you have
Exchange Server and HCL Domino next to Microsoft 365, Google and Outlook.com. No forced move to the cloud.
Made for business
For IT teams, companies and service providers. No consumer tricks and no fine print.
Plain and honest
Clear plans, clear limits and a person who answers email. We say what is not supported.
Where we work
A small team, spread across three places, on one schedule.
Engineering and support
Our developers and support team work on Central European Time, Monday to Friday.
The company
Hadar Company S.A. is the company behind AddSync. It is registered in Panama.
UK representative
Mountain Professional LTD in London is our representative for data protection in the UK.
Questions about us
Who is behind AddSync?
AddSync is built by people who have run business IT and mail systems since 1994 and Exchange hosting since 2008. The company behind it is Hadar Company S.A., registered in Panama.
Where is the team?
Engineering and support are based in Poland and work on Central European Time. The company is registered in Panama, and our UK representative is Mountain Professional LTD in London.
Is AddSync for consumers?
No. AddSync is built for companies, IT teams and managed service providers.
Why did you build AddSync AI?
Companies want their people to use AI with mail and calendars, but they cannot hand over mailbox passwords or send everything to an AI tool. AddSync sits in between as a guard, with filters, human approval and a journal.
Does AddSync work with on-premises systems?
Yes. Exchange Server 2016, 2019 and Subscription Edition and HCL Domino work next to Microsoft 365, Outlook.com and Google.
How can I talk to you?
Write to contact@add-sync.com or use the contact form. A person answers.
