Fix GSMMO Migration Dates in Apple Mail
Why GSMMO Migrations Show the Wrong Date in Apple Mail
When GSMMO migrates emails from Outlook PST files or Exchange profiles into Google Workspace, it sets the INTERNALDATE to the upload timestamp. Users who subsequently connect Apple Mail to their Google Workspace account via IMAP see every migrated email dated to the GSMMO migration day. Apple Mail on macOS and iOS reads the IMAP INTERNALDATE to determine the date displayed next to each message.
Apple Mail does not parse the Date header from the email body for its list view date display. Unlike the Gmail web interface (which uses the Date header and may show correct dates), Apple Mail relies entirely on the server-provided INTERNALDATE. This means the migration date is the only date Apple Mail displays, with no way for the user to see the original date without opening each message and inspecting the full headers manually.
Mac and iPhone users who migrated to Google Workspace using GSMMO and use Apple Mail as their primary email client are fully affected. Their inbox, sent items, drafts, and archived messages all display the migration date. Smart Mailboxes in Apple Mail that filter by date produce incorrect results, and the chronological thread of email conversations is lost in the message list view.
How This Affects Apple Mail
Apple Mail on macOS displays the INTERNALDATE in the message list. After a GSMMO migration, every email shows the migration date regardless of when it was originally sent or received. The "Date Received" column in Apple Mail's column view shows the migration timestamp for every message. Sorting by date groups the entire mailbox under a single date.
On iOS, the Mail app behaves identically. The inbox view shows the migration date next to each message. Smart Mailbox rules on macOS that use "Date Received is in the last [X] days" either catch everything (if the migration was recent) or nothing (if the migration was weeks ago). Spotlight search on macOS, which indexes Apple Mail messages and allows date-based filtering, also uses the INTERNALDATE, so system-wide email search by date returns incorrect results. The issue permeates the entire Apple ecosystem's email experience.
Frequently Asked Questions
Does Apple Mail have any setting to show the Date header instead of INTERNALDATE?
No. Apple Mail always uses the IMAP INTERNALDATE for its date display in the message list. There is no user-configurable option to change this behavior. The only way to show the correct date is to fix the INTERNALDATE on the server.
Will fixing the dates affect Apple Mail on both Mac and iPhone?
Yes. Redate.io fixes the email at the server level. Once the INTERNALDATE is corrected in the Google Workspace account, Apple Mail on macOS, iOS, and iPadOS all display the correct date automatically after syncing.
Can I use Redate.io with my personal Gmail account after GSMMO migration?
Redate.io supports both Google Workspace accounts and personal Gmail accounts. If GSMMO was used to migrate emails into any Gmail-based account, Redate.io can scan and fix the affected messages.