Fix Manual IMAP Copy Dates in Apple Mail
Why Manual IMAP Copy Shows the Wrong Date in Apple Mail
Apple Mail on macOS allows users to add multiple IMAP accounts and drag messages between them. This is a common method for consolidating email from several providers or migrating from one service to another. When Apple Mail copies a message to the destination IMAP server, it uses the IMAP APPEND command without specifying the original INTERNALDATE. The destination server records the upload timestamp as the message's INTERNALDATE.
Apple Mail's message list displays the date based on the server's INTERNALDATE, not the Date header from the email. After a manual IMAP copy, every transferred message shows the copy date in Apple Mail's inbox and folder views. Unlike Thunderbird (which can display the Date header column), Apple Mail does not offer a column option that shows the original Date header. Users see only the corrupted date in the message list.
Mac users who drag emails between IMAP accounts in Apple Mail typically expect the operation to be transparent. Apple Mail provides no warning that dates will be lost during the copy. The date corruption is only discovered after the operation completes, when the user notices that all copied messages now display the same date. If the originals were deleted from the source account, the correct dates are no longer visible in any client without fixing the INTERNALDATE.
How This Affects Apple Mail
Apple Mail on macOS and iOS shows the copy date for every manually transferred message. The message list view, which is the primary way users interact with their mailbox, displays the INTERNALDATE. There is no built-in option to show the original Date header instead. Every copied message appears as received on the day the copy was performed.
Apple Mail's Smart Mailboxes, which filter messages by criteria including date, produce incorrect results for copied messages. A Smart Mailbox configured to show "messages received in the last 30 days" either includes all copied messages (if the copy was recent) or excludes them all (if the copy was more than 30 days ago). Spotlight search on macOS indexes Apple Mail messages using the INTERNALDATE, so system-wide searches filtered by date also return wrong results. The corrupted dates cascade through the entire macOS mail experience.
Frequently Asked Questions
Does Apple Mail have any way to preserve dates during IMAP copy?
No. Apple Mail does not support specifying the INTERNALDATE during IMAP APPEND. All messages copied between IMAP accounts via Apple Mail receive the copy date as their INTERNALDATE. This is a limitation of how Apple Mail implements the IMAP copy operation.
Will Redate.io fix dates in Apple Mail on both Mac and iPhone?
Yes. Redate.io fixes the INTERNALDATE at the server level. Once corrected, Apple Mail on macOS, iOS, and iPadOS all display the correct date after syncing with the server.
I copied emails from multiple accounts into one via Apple Mail. Can everything be fixed?
Yes. Redate.io identifies affected emails by comparing the INTERNALDATE with the original Date header. Regardless of how many source accounts were consolidated, all affected messages in the destination account can be fixed in a single operation.