Convert Maildir files from Linux Servers

To do this:

1. Download Maildir from server: Use SCP, SFTP, rsync or FTP to copy the Maildir directories to your Windows machine
2. Typical server locations:
   • Dovecot: /var/mail/vhosts/domain/user/ or ~/Maildir
   • cPanel: /home/username/mail/domain/user/
   • Plesk: /var/qmail/mailnames/domain/user/
3. Install and run the converter: Browse to the downloaded Maildir folder
4. Auto-detection: The tool recognizes cur/new/tmp structure automatically
5. Convert: Select output format and convert

Maildir format is supported by many popular Linux/Unix mail servers:

• Dovecot, The most popular open-source IMAP server, uses Maildir by default
• Courier Mail Server, Created Maildir++ extension with subfolder support
• Postfix, When configured with home_mailbox = Maildir/
• Qmail, Original creator of Maildir format
• Exim, Supports Maildir delivery format
• cPanel/WHM, Uses Dovecot/Courier with Maildir
• Plesk, Stores emails in Maildir format
• DirectAdmin, Supports Maildir storage

If your Linux mail server stores emails in individual files within cur/new/tmp directories, it's using Maildir format.

Yes, absolutely. The converter is specifically designed to handle the file-per-message storage model efficiently:

• Fast scanning: Efficiently scans directories with thousands or millions of files
• Memory management: Processes files in batches to handle large mailboxes
• Progress tracking: Shows real-time progress for long conversion operations
• Every subfolder: Automatically processes all nested Maildir++ subfolders

We've tested with mailboxes containing over 500,000 individual email files. The Enterprise license is recommended for very large server migrations.

The converter automatically preserves your complete folder hierarchy:

• Maildir++ naming: Folders like .Sent, .Drafts, .INBOX.Clients are converted to proper folder hierarchies
• Dot-prefix handling: The leading dot and folder separators are correctly interpreted
• Nested folders: Deep subfolder structures (e.g., .INBOX.Work.Projects.2024) are fully supported
• Special folders: INBOX, Sent, Drafts, Trash are mapped correctly

The output will have the same logical folder structure as your original Maildir, regardless of the output format (PST, MBOX, EML folders, etc.).

The Maildir Converter can convert it to mbox format and back again.

To migrate from Dovecot to Outlook or Exchange:

1. Locate Dovecot Maildir: Typically at /var/mail/vhosts/ or user home directories
2. Download to Windows: Use SCP or rsync to copy the Maildir directories
3. Convert to PST: Use the Maildir Converter with PST output format
4. Import to Outlook: File → Open & Export → Import/Export → Import from PST
5. For Exchange/O365: Use the PST import wizard in Exchange Admin Center or Outlook migration tool

The Business/Enterprise license includes direct IMAP migration to Office 365 without a PST file in between.

Yes. Both cPanel and Plesk store user emails in Maildir format:

cPanel backup structure:

Plesk backup structure:

Steps:

1. Extract the backup archive (tar.gz, zip)
2. Navigate to the mail directory
3. Point the converter to the Maildir folder
4. Convert to your desired format

The converter handles the Maildir++ format used by these control panels, including all subfolders and quota files.

No, you can skip it. The tmp folder only holds messages that are still being delivered. On a copy or a backup it is usually empty or holds stale files, and none of it is mail you need. Copy the cur and new folders and the dot-folders such as .Sent and .Drafts. Those hold every real message.

That is usually correct, not a fault. Maildir records read state by where a message sits and by the flags in its filename. A message in the new folder, or one in cur without the S flag, was never opened on the server, so it stays unread after conversion. Messages that carry the S flag come across as read. If every message looks unread, the source flags were probably lost before conversion, for example by copying the files with a tool that renamed them.

Not directly. Thunderbird reads MBOX, not Maildir, so there is no import Maildir button. Convert the Maildir to MBOX first, then import the MBOX with the ImportExportTools NG add-on. The idea that Maildir cannot be used with Thunderbird at all is wrong. You convert it to MBOX and it imports fine.

It depends on what you have. If the source mailbox is still live on a server, doveadm (Dovecot's own tool) or imapsync copy mail straight to another server or mailbox over IMAP at no cost, and that is the cleaner route. A converter is the better choice when the server is gone or you only have a backup of the files. It also fits when you need the mail in a file format like Outlook PST or PDF instead of another live mailbox.