A mail export can look complete while still leaving important details behind. A message may appear in the new account, for example, but have a missing attachment, an unexpected date, or no trace of the folder it came from. What survives depends on the export format, the mail app, and the import process. Before relying on a migrated mailbox, check each of those details with a few representative messages. Keep the original account available until you have confirmed the imported copy contains what you need.
The useful bits
- Inspect exported files and a sample of messages; do not assume an export includes every field.
- Compare message text, attachments, dates, and folder locations after import.
- Keep the original account until your checks are complete and any gaps are addressed.
Start with the export’s limits
“Export” can describe different things: a collection of individual message files, an archive intended for another mail program, or a format used by a particular service. The label alone does not tell you what it contains. Some formats can preserve message headers and folder structure; others may save messages in a way that requires extra steps to restore them. Attachments may be embedded in a message or represented separately.
Before importing, note the export format and look for any included instructions, summary, or file listing. Check that the archive opens and that its contents are more than just a list of message subjects. If you cannot tell whether a format preserves a detail you need, treat that detail as unconfirmed until you inspect the imported result.
Check the message itself, not just its subject
Choose a few messages that matter for different reasons: one with a long conversation, one with an attachment, and one from a folder you plan to keep. In the exported copy, open the message and confirm that the sender, recipients, subject, and readable body are present. For a conversation, check whether the earlier replies appear in the expected order rather than assuming the latest message represents the whole thread.
Some exports retain technical headers that are not shown in the normal message view. Those can help identify a message, but they do not substitute for checking that its visible content is readable after import. Compare the same message in the original account and the imported copy.
Verify attachments separately
A message that displays an attachment name does not by itself prove that the attachment is present or usable. Open or download the file from the imported copy, and check that it has a plausible name and can be opened by an appropriate application. For a file that is important to you, compare it with the copy in the original account. Do not assume that every export or import route handles every attachment type the same way.
Keep the check focused on the files you depend on. If an expected attachment is missing, unusually small, or cannot be opened, preserve the original message and attachment while you investigate another export or import method.
Compare dates and folder paths
Dates can be confusing because a mail app may show a received date, a sent date, or a time adjusted for the account’s time zone. Compare the date shown for the same message in both accounts, and check whether a difference is a changed day or simply a display-time shift. If the exact time matters, inspect any date details the export format makes available rather than relying on the inbox list alone.
Folder names can also change during migration. A message might be imported into the inbox, placed in a new folder, or lose a nested folder’s original path. Check several folders, including one with subfolders if you have them. If the destination uses different folder names, write down how each important source folder maps to its new location.
Use a small, deliberate verification sample
A short checklist makes gaps easier to spot than a quick glance through the inbox. Select messages from different years or periods, folders, and message types. Include at least one message with an attachment and, if relevant, a conversation with multiple replies. Mark each item as checked only after opening it in the imported account.
- Message: sender, recipients, subject, and body are present.
- Attachment: the expected file is present and opens.
- Date: the displayed date makes sense when compared with the original.
- Folder: the message is in the intended destination folder.
- Coverage: the export includes the periods and folders you meant to move.
Source: [sender@example.com], folder [Projects/Planning], date [date shown in original] Imported: [same message found], body [checked], attachment [opened or not applicable], destination [folder name] Result: [complete / follow-up needed]
Keep the source until the destination is dependable
Do not close, delete, or give up access to the original account just because an import finishes. Keep it available while you check representative messages and resolve anything missing. If you use a mail app to connect to a mailbox, BITTU Mail’s published IMAP settings are mx1.bittuicloud.com on port 993 with SSL/TLS. Use the settings provided by the service you are moving from for the source account, and never accept a certificate warning. Connection does not itself confirm that a separate export or import preserved every detail.
When your checks are complete, record any limitations that remain and keep a separate copy of the export if you need one. If a gap appears, return to the original message, make a fresh export if appropriate, and verify the replacement in the destination before relying on it. A successful import is a useful milestone; the message-by-message checks are what show whether the copy meets your needs.
About this guide
Prepared with AI assistance for the BITTU Mail editorial library. Check important details against your original messages and current account settings. Product access depends on your role, plan and provisioning state. Provider interfaces and requirements can change.
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