This Go script splits a large mbox file into smaller parts, each containing a maximum number of emails. The split files are named based on the date of the first email in each part. This is useful for managing large email archives and improving performance when processing email data.

1. Make sure you have Go installed.

2. Clone this repository:

   git clone https://github.com/VadimOnix/mbox-splitter.git
   cd mbox-splitter

3. Build the executable:

   go build

./mbox-splitter <path to mbox file>

For example:

./mbox-splitter /path/to/my/large.mbox

This will create multiple mbox files in the current directory, named like this:

mbox_part_<number>_<date>.mbox

Where:

• <number> is the sequential part number (starting from 0).
• <date> is the date of the first email in that part, in YYYY_MM_DD format.

• maxEmailsPerFile: The maximum number of emails per output file. This is controlled by the maxEmailsPerFile constant in the main.go file and is currently set to 1000. You can modify this value in the source code if needed.
• bufferSize: The buffer size used for writing to files. This is controlled by the bufferSize constant in main.go and is set to 4096 bytes. You can adjust this value as needed.

Let's say you have a large large.mbox file. Running:

./mbox-splitter large.mbox

might produce the following output files:

• mbox_part_0_2024_09_22.mbox
• mbox_part_1_2024_09_23.mbox
• mbox_part_2_2024_09_24.mbox
• ... and so on.

The script includes error handling for file operations and will print error messages to the console if any issues occur.

Contributions are welcome! Please feel free to open issues or submit pull requests.