How to Split & Merge MBOX files via MBOX Splitter/Merger?

Split MBOX files into smaller parts and merge two or more MBOX files into a single file with all emails & attachments.


Download and use eSoftTools MBOX Splitter and Merger Software, software to break MBOX files into several small parts and merging two or more MBOX files into a single file. Split and Merge MBOX files with different mode and get the instant results without errors. At one time, merge and split multiple MBOX files without losing a single email or other information.

Step-1) Download and launch eSoftTools MBOX Splitter & Merger Software on your windows PC.

Press the Add File/Folder button from first screen of the software.

MBOX Splitter & Merger Software Main Screen
Step-2) Choose a file selection mode from the options.
  • Select MBOX file: - Manually add a single MBOX file at a time
  • Select MBOX Folder: - Add complete folder having multiple MBOX files.
  • Auto Load Thunderbird Profile: - In a single click load all Thunderbird profile mail folders.

Add required MBOX files and press the Next button.

add/load MBOX files
Step-3) Load all mail folders and items from MBOX files into the software, choose needed folders and press Split/Merge button.
open/view MBOX files

After MBOX mail folder selection, apply the steps shown below for MBOX file splitting and merging: -

Split MBOX file to separate files by applying below given steps: -
Step-4) Choose "Split MBOX file" option and hit the Next button.
split mbox file
Split MBOX files by Size
Step-5) Select Split by size from MBOX splitting options and apply other settings.
  • Define size: - Input the size of in which you want to split MBOX files.
  • Filter Mail: - Select start and end date and split MBOX files with emails of only chosen dates.

After all selections, click the Next button.

Split by size
Split MBOX files by date
Step-5) Select the Split by date option, and apply date filtering.

Date filter: - Choose a "Start" and "End" and split MBOX files with emails of only specified dates.

split by date
Split MBOX files by Year
Step-5) Choose the Split by year option from split options list and apply year selection settings.
  • Select Year: - Make selection of a "Start" and "End" year to split MBOX with emails of specified years.
  • Custom Year: - Input start and end year in "From" and "To" field and split MBOX files with emails of selected years.
MBOX file split by year
Split MBOX files by Email Address
Step-5) Choose Split by Email Address option from splitting options, input email address of To, From, CC, and BCC field and split MBOX files with emails of specified email addresses.

Note: - Also, split MBOX files by email subject. Enter subject of email and split MBOX files with emails of specified subject.

Filter Emails: - Select mail filter option, choose a start and end date to split MBOX files with emails of chosen dates.

splitting MBOX by email address

Step-6) Select a location from local drive for saving resultant MBOX files after splitting.

Lastly, press the Split button and start the MBOX file splitting process.

Split MBOX file process complete
Merg two or more MBOX files in single MBOX file by applying these steps: -
Step-4) After choosing mail folders, click the Split/Merge button and choose Merge MBOX file option, then hit on Next.
merge mbox files
Merge MBOX files with all items
Step-5) Select Merge All Items option from merging options.

Note: - Use this option to merge MBOX files with all their inner email items without filters.

Split by size
Merge MBOX files by date
Step-5) Select Merge by date option, and apply date filter settings.

Date filter: - Select a "From" and "To" to MBOX files with emails of only specified dates.

merge by date
Merge MBOX files by Year
Step-5) Choose the Merge by year option and apply year selection settings.
  • Select Year: - Choose of a "Start" and "End" year to merge MBOX with emails of chosen years.
  • Custom Year: - Enter start and end year in "From" and "To" field for merging MBOX files with emails of selected years.
MBOX file merge by year

Step-6) Choose a saving location from local drive to preserve resultant MBOX files after merging.

Lastly, press the Merge button and start Merging MBOX files.

Merge MBOX file process complete