In Todd Pohokura Ltd v Shell Exploration NZ Ltd(1) the High Court considered the discovery obligations of parties to litigation with regard to the correct treatment of emails forming part of an email chain created by use of the function which quotes prior emails in reply. The decision addresses the question of whether a record of an earlier email communication within an email which quotes all prior communications by way of reply (ie, an email chain) is a separate document in itself or part of a single document.


The parties in this case, Todd, Shell and OMV, were parties to a joint venture. Shell and OMV made certain decisions regarding the venture despite Todd's opposition. Todd commenced proceedings against Shell and OMV. The parties had already carried out discovery in the litigation and the issues before the court involved several interlocutory applications by the parties relating to further discovery or further particularization of listed documents.


The application for further discovery by OMV related to email chains. In each case the subject email appeared as part of the sequence in a chain in which the email replies before and after the discovered email were redacted. Therefore, it appeared that Todd had given discovery on the basis that each record of a prior communication quoted in a single email was a separate document. Presumably for matters of convenience, only the final email in the chain had been retained and produced, rather than each of the prior sequential emails, but each prior component email was separately identified.

OMV claimed that treating each prior email record as a single document, with redaction of the rest, prevented it from placing the discovered email correctly in the sequence of communication. OMV argued that each chain email document comprised a single document for discovery from which redaction was not allowed.

Todd resisted the application on the basis that a email comprising a chain does not constitute a single document; rather, each email record within the chain is separate and distinct. Therefore, there is no requirement to place each such email within the chain. The court upheld this argument, although the judge noted that it had "unfortunate consequences in creating work" and expressed the hope that where cooperation in litigation was possible, some form of group listing of emails could be agreed upon to enable discovery obligations to be kept within sensible bounds.

Todd made an application against both Shell and OMV for component emails to be individually numbered and listed in the discovery list. The lists, which were substantial, had evidently been prepared in circumstances of urgency. Shell's list apparently dealt with chains of emails as a single document particularizing the details of only the last email in the chain and presumably omitting from the discovery list the details of the earlier communications that made up the chain.

The court held that each email record within a final email constituted an individual document and that the independent nature of such emails could not be subsumed merely because it was part of a chain. A list must set out the details of each email in a chain in order to allow an opposing party to analyze the full extent of the contribution made by a particular individual to the ongoing dialogue, which would be impossible if only the last email in the chain were listed. Shell was ordered to file an amended affidavit that accurately particularized each individual email within a chain.

The court had no difficulty in holding than an email chain could be partly redacted and partly discovered, as each component email was a separate document. It held that an individual email could not be partly redacted within itself, unless the purpose was to remove irrelevant information. This further demonstrates the court's approach to email chains as not representing a single document, but comprising several documents, with each quoted prior email record being a separate document capable of being excised from the rest of the chain. Therefore, a redaction of some of the emails in the chain was not regarded as a redaction within a document.

Unfortunately, the decision does not make the surrounding discovery circumstances sufficiently clear for practitioners to be able to extract clear principles with complete confidence. Having regard to the nature of the recorded argument, it must be assumed that the parties had adopted a discovery shortcut of producing only the final document in a series of emails which, because of the 'reply with copy' function, quoted all of the prior emails in the sequence. Shell had listed only the last in the chain, whereas Todd and OMV had listed each quoted prior individual email separately. Strictly speaking, as each of the emails in the sequence was a separate communication, discovery required that each email be discovered as it had been received and sent - the result of a 20-email exchange would therefore have been 20 emails of progressively greater length. In this case, it appears that what had been produced was only the last email in the chain.

If this practice is adopted for reasons of practicality, the analysis adopted by the court is a logical consequence. In those circumstances, the email is being produced not only as itself, but also as a form of copy of all prior communications in the chain. If the practice is adopted, the individual communications should be numbered and listed separately and analyzed separately for relevance and privilege. Although this practice has its benefits, there are dangers which should be recognized and the practice should be adopted only if the potential disadvantages are not apparent.

The first danger is the ready but sometimes incorrect assumption that an email chain has integrity and is complete. Senders do not necessarily quote in full all prior emails in the sequence - they may modify the quoted portion, possibly by eliminating irrelevant or inappropriate messages which they do not wish to pass on. If adopting the pragmatic shortcut of using a chain to discover a sequence, it is vital to check the chain carefully against the original communications for accuracy and completeness. Faced with such a task, it might be easier to discover each email separately at each stage of the chain, as best practice dictates, so that each communication (composed of an email with quoted copies of preceding emails and attachments) is sure to be discovered. Parties to litigation should consider whether to accept discovery only of the last document without an assurance from the discovering party on this point.

The second disadvantage is apparent from the decision itself. By adopting the chain fiction (ie, that the final email is a series of separate documents), the receiving party loses any benefit of treating the document as a whole, including an entitlement to see the whole chain, subject to the ability of the discovering party to justify a redaction, as it would have to do in any single document. Sometimes an email will respond directly to the issues or questions of a preceding email and will lose its meaning if considered in isolation - for example, an email may respond to a quoted question with the word 'no', in which case the omission of the quoted question would render it meaningless.

The court's approach ignores the reality the the recipient did not receive an email which simply read 'no' - no such email ever existed. Rather, the email that was received consisted of the last reply - 'no' - and the preceding quote which gives the communication its meaning. To discover an email which forms only part of the communication is, in effect, to create a new document that never existed in the form in which it is discovered.

Discovery on this basis may have dangerous implications for relevancy decisions. The persons carrying out discovery will ask themselves whether an email makes the allegations in contention either more or less likely. In the case of an email reading merely 'no', they may conclude that it is not at all helpful and therefore irrelevant - assuming blindness to the preceding emails. However, the email may be crucial when considered in its proper context and with its full content intact.

The scope for error on both sides of the discovery process is disturbing. If discovery is given strictly (ie, if each of the progressively longer emails is produced), the receiving party will be entitled to argue that each email was a single document which must be separately discovered in its entirety, including the quotation of prior communications. As a single document, an email chain will be either privileged as a whole or not privileged; it is impossible to carve up the communication into privileged and non-privileged parts by redacting some emails in the chain and not others. The difficulty in the court's approach is clear when other forms of communication are considered. When a solicitor writes a letter quoting some otherwise non-privileged material, those quotations properly form part of the solicitor's communication and will be privileged. It would be absurd to redact the rest of the solicitor's privileged communication while discovering the quoted section of earlier correspondence. By analogy, a privileged email that quotes preceding emails is a single document. The quoted emails are part of the privileged communication and should not be discovered in isolation from that context. The proper way to separate privileged and non-privileged emails where they form part of a common chain is to discover each email in sequence in the chain separately.

It is hoped that there will be no attempt to apply the analysis adopted in this case - which is suitable for discovery only of the final email in a chain - to more strictly provided discovery, as the result would be a great increase in work. In the case of a final chain of 20 emails, the number of discovered emails would rise from 20 to 210 if each quoted prior email in each chain had to be treated separately. In addition to the resulting unnecessary duplication, there is also likely to be considerable conceptual confusion regarding the treatment of component parts of a single document for both relevance and privilege. It will be interesting to see how this decision affects discovey practice in future.