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Email threading groups related emails into coherent chains based on their metadata and content. This section explains the criteria and methods used by the platform to determine email threading:

Email field extraction

The following metadata fields are extracted for the primary message (topmost email header) and the embedded messages (inline headers).

Exact Matching Criteria

Epiq AI performs textual matching of the following email fields. Exact textual match ignores whitespaces and punctuations.

Email sender/recipient matching

  • Exact match of the FROM, TO, and CC fields extracted from messages

Email sent date matching

  • Epiq AI normalizes all time stamps in UTC and compares the time differences. If the time zone is available, maximum allowance is 1 hour. If time zone is unknown, maximum allowance is 24 hours.

Email subject matching

  • A normalized subject must satisfy exact textual match. Email subjects are normalized by removing prefixes like “RE:”, “FW:”, and variations of these, to identify consistent subjects across threads.

Email Body Matching

  • Textual matching of the Body content
  • Inline quoted text, when applicable
  • In cases where exact matches are not satisfied, a shingling method is used, which breaks down the comparing texts into overlapping sequences of words (unigrams and bigrams). If the comparing texts exceed the threshold proportion of shared shingles (default value is 0.99) then they are considered a match.

Features Ignored

  • BCC field is ignored in the email matching.
  • Footers, common disclaimers, and email signatures are ignored.