Update: November 14, 2025
We plan to offer a paid Backup Period Extension Option for customers who desire a retention period exceeding 10 years, after January 2027.
We are currently preparing for the start of sales, and we anticipate that it will take some time before the option becomes available. We apologize for the inconvenience, but customers who wish to extend their backup period are kindly asked to contact us.
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Customers using HENNGE Email Archive
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Thank you for using HENNGE Email Archive.
We would like to inform you of upcoming changes to the retention period settings for email data in HENNGE Email Archive.
■ End of "Perpetual" Retention Period
The data retention period of HENNGE Email Archive is based on your contract.
For customers currently using the "perpetual" retention setting, this feature will be discontinued on December 31, 2026.
Starting from January 2027, the retention period will gradually be changed to a maximum of 10 years for the following customer tenants.
■ Affected customer tenants
- Customers contracted under HENNGE One Pro
- Customers on legacy plans (other than HENNGE One Pro) with retention settings of "perpetual" or more than 10 years
From January 2027, any email data exceeding the 10-year retention period will be automatically deleted through monthly batch processing.
For the following plans, there will be no change from the existing 10-year retention period:
■ Unaffected customer tenants
- Customers who newly subscribed to HENNGE One Basic and HENNGE ARC after October 2021
■ About the email data retention period
Our email archive service stores data in two areas: Real-time Period and Backup Period.
Please refer to the following Help Center article for the differences between these two storage types.
Reference article: How to use the backup function
The default Real-time Period is 1 year.
Customers who have extended the Real-time Period through an optional contract can continue using it as per their current contract. This is independent of the 10-year maximum retention period.
■ How to check your retention period
You can check your current retention period in Email Archive Modern under [Archive Period Settings].
Reference article: [Email Archive Modern] How to log in to the Administration
※ As part of ongoing improvements, we are offering Email Archive Modern, a major renewal of the Email Archive service.
It includes many enhancements and will continue to be updated regularly.
We encourage you to take full advantage of the new version.
Reference article: Announcement of the official release of Email Archive Modern
According to our independent research, under Japan’s Electronic Book Storage Act, email data must be retained until the statutory retention period specified by each tax law expires.
The Corporation Tax Act and Income Tax Act require retention for 7 years, with 10 years considered appropriate in special cases.
This change to the data retention policy is due to the increasing AWS operational costs and the need to optimize development resources for our long-term product roadmap.
We appreciate your understanding as we continue striving to provide stable and reliable services.