October 2025: Transition to Zimbra 10

We are excited to announce the upcoming upgrade and migration of our Zimbra email servers to Zimbra 10.1, with exciting new features to enhance your email experience. For more details, see: What's new in store with Zimbra 10?

Version 10.1 is the latest major release of the Zimbra email and collaboration platform, bringing a host of new features and improvements.
This upgrade focuses on enhancing usability, performance, and security, ensuring that you have a more efficient and enjoyable experience.

Summary

Migration Starts Soon: Originally planned for October 31st, our Zimbra server migration to Zimbra 10 has been postponed to Friday November 7th 2025 after 10 pm EST.

Minimal Disruption: We will do our best to minimize the disruption, although data on mobile and IMAP devices will need to re-sync.
See further below for recommendations to minimize sync inconvenience if you have a large mailbox.
In any case, you will be able to use HIS webmail while your apps re-sync data.

HIS Zimbra Webmail will remain available at all time:
Your mailbox will keep the familiar “Classic” view after the move.
Your day-to-day use of HIS Zimbra webmail during the migration should remain unaffected.
You may see the new web address of our webmail is now: https://securemail.his.com - don't worry: the old web addresses will still work.

Freeze period: There will be about a week in October while we are copying the data over to the new Zimbra servers when we will not be able to add any new Zimbra email account. Thank you for your understanding and patience.

At the time of the switchover October 31st 2025 after 10 pm EST.:
There might be a few minutes interruption while we switch connections to the new servers. This process is designed to be smooth and should not cause any noticeable disruption and you will be able to use your mailbox as usual.
After that the most recent messages will be copied to your email account overnight within a few hours, although it may take more for large mailboxes.
Note: If you happen to be logged in to webmail during the switch, you’ll see an update notice once this takes place. Click “Yes,” and after a few moments, you’ll be back in your webmail.

Email apps:
The transition should be smooth and you should not have to change anything to your current settings. All credentials will be moved to the new servers.
However, most mobile and email apps will re-sync the content of the mailbox after the migration.
See further below how you can minimize it if you have a large mailbox.

If you have a large mailbox:
Minimize the time it will take to sync your messages once switched over to Zimbra 10 by shortening the number of days your email app syncs mail for:

Outlook Connector (ZCO):
This feature is only available for our Professional level of accounts.
Only If you are already using Outlook for Windows with Zimbra Outlook Connector (ZCO): See instructions.

Things that will NOT be moved to the new server:

2FA authentication
The credentials for 2FA authentication can not be ported over to the new server - you will have to re-create them and update your email apps.

Shares
If you are sharing any folders with a 3rd party, you will have to re-create those shares.

Important Notes:

Minimizing email re-sync after migration

When a user’s mailbox is moved to a Zimbra 10 server, sync tokens are reset, causing mobile or IMAP clients to re-sync the entire mailbox. Users may notice their email disappearing from their phone or IMAP client temporarily until it reappears after the re-sync completes. This may happen a few times, especially for users with large mailboxes or many folders.

As a result of this, if you have set a long sync period on your device, we strongly recommend that you now set this as short as possible (e.g., two weeks), ahead of the upgrade. Once your mailbox is migrated to Zimbra 10, you may then extend the sync period to what it was previously. This will speed up the re-sync process.

Note: Apple mail clients have short timeouts and request the entire mailbox folder tree to refresh before syncing any emails. If you are on a slow Internet connection, the mailbox may appear to populate and then disappear, indicating the folder refresh did not complete in the time Apple allows. For this reason, it is best for the mobile device to be on a fast wireless connection to minimize disruption.
Let it do its thing for a few hours.

Keep in mind that if you are facing any inconveniences, you may always chose to use the new server HIS webmail interface in the meantime.


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