Email Splitter

Email Splitter is a data processing utility that converts a single large list of recipient addresses into multiple download-ready files. It supports common formats such as CSV and plain text, preserves a header row when present, and enforces a configurable maximum per-file size. The primary users are marketers, CRM administrators, and data teams who need to meet per-file sending limits, improve deliverability, or prepare lists for segmented campaigns. The tool avoids introducing duplicates across segments when deduplication is enabled and maintains the integrity of the original email data.

Under-the-hood, the tool applies a segmentation algorithm that computes the number of segments as ceil(total_emails / segment_size) and slices the input accordingly. It can deduplicate emails using a case-insensitive match, optionally sort entries, and produce separate segment files with consistent headers. Validation steps catch malformed lines, empty entries, and non-email tokens, and the system reports any segments that would violate size constraints.

Use cases include pre-splitting large distribution lists for sending platforms with per-file limits, exporting compliant chunks for data governance, and enabling incremental imports into CRM tools. Unique value lies in preserving header integrity, offering configurable segment sizing, and returning ready-to-download files without manual editing. The tool is deployment-agnostic and suitable for batch processing pipelines, data hygiene initiatives, and campaign preparation workflows.