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Find and remove duplicate emails

5 October 2026 · searched as remove duplicate emails

Import the same PST twice, or an export of mail you also sync, and every message is there twice. MailCode finds the copies across every account and import, shows you each group, and removes only what you tick.

How to do it

Open Settings ▸ Storage and click Find duplicates (everything).
A list of groups opens — ⧉ 312 duplicate groups · 640 copies — each copy with its folder and date. Nothing is ticked yet.
Search it by subject, sender, folder or date, or use the Folders checkboxes to see one import at a time.
Click Keep oldest to tick every copy but the first in each group, check the list, and click Remove.

MailCode: Find duplicates: each group of copies, the oldest kept. — Find duplicates: each group of copies, the oldest kept.

Two copies match on their Message-ID, or on sender, subject and a time within two minutes. Removing is permanent — copies do not go to Recently Deleted, and .eml files on disk are left alone. Select all shown ticks every copy, the oldest too, so use Keep oldest to keep one. After a scan, the copies wear a ⧉ badge in the list until you clear the marks.

MailCode is a mail client for Mac and Windows that keeps your mail in a searchable archive on your own disk. Free for 14 days.

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