Why Mobile Data eDiscovery Is Different Than Email eDiscovery

It’s 2021, which means it’s highly unlikely that this is the first blog post you’ve read saying you need a mobile data eDiscovery plan. Most of us get that by now.

However, you can’t always take the same technology and approaches you’re currently using for email and superimpose them on mobile data. It just doesn’t work that way. Unfortunately, it can be hard to wrap your head around just how different texting and email really are until you’re neck deep in a project.

Today, we wanted to walk through some of the main things you need to account for while collecting, processing, and reviewing mobile data. By understanding the differences between these channels, you can not only ensure that you’re including mobile data in your eDiscovery strategy, but that you’re doing it right.

“Texting” is actually 3 different things that LOOK like 1 thing.

Generally speaking, emails are emails. After the initial collection, it doesn’t really matter much if those emails came from Macs or PCs, or if the company ran their emails through Microsoft 365 or Google Drive. Emails can be imported into a review platform, and reviewers don’t really have to care that much about where they initially came from.

What a layperson thinks of as “texting” is actually a combination of as many as three different types of communications: SMS, MMS, or iChat. We act like they’re the same thing because generally, our phones make them look like one thing. I don’t have a separate app for sending SMS messages vs. MMS messages. My phone doesn’t yell at me when I reach the character limit for an SMS, it just automatically converts it without me having to think about it.

During data processing, these messages that seem identical on the front end often get sorted out into different buckets on the back end. That means that if custodians were iChatting, lost wifi, and then switched to SMS, that single conversation may get ripped apart and reviewers have to piece it back together.

When you’re identifying potential sources of data, it’s important not to just ask about “texts.” If possible, try to figure out how texts break down into SMS, MMS, and iChat. The best mobile data eDiscovery technology can thread these messages together, and depending on how many phones you’re collecting, it might be worth that investment. At the very least, making sure you know how texts break down into SMS, MMS, and iChats helps you better assess how long review should take.

Mobile Communication Has No “Subject Line” 

Most work emails have a subject line; generally, emails in that same conversation also have that subject line. Sure, sometimes conversations naturally flow away from that initial subject, but at least it’s a valuable starting point that helps discovery teams understand what messages belong together, and which ones might be duplicates; this is the basis of how review platforms utilize email threading.

Not only does texting lack a “subject line,” it’s also a place where users simply don’t even try to sort their conversations out into multiple threads the same way. Earlier today, I frantically texted my mother about a jacket I left at her house, and within minutes she was asking me to text her a recipe for banana cake.

Those two conversations coexisted in the same thread, with messages right on top of each other. That’s just how a lot of us text. I pity any review team that would have to go through my phone and find messages relevant to their case with so many less relevant messages randomly scattered across my conversations. (On the bright side, they might get a nice banana cake recipe out of it!)

Threading messages into conversations is one of the most important things that any good review platform does for reviewers; it’s even more important when users aren’t naturally “threading” their conversations together by default.

Mobile Communication Usually Requires More Redactions

On a related note, professional communication is more likely to co-mingle with personal communication in text messages compared to email. That’s especially true in companies where employees still use their personal device for company business. With email, we tend to have a dedicated work account apart from our personal email account. Users understand that there’s no reasonable expectation of privacy in their work emails. That’s not always true in mobile, particularly at companies that don’t issue company-owned phones or have clear Bring-Your-Own-Device (BYOD) policies.

What if that thread where two work friends texted about trade secrets also mentioned things like doctors’ appointments or included pictures of their kids? Legal teams need to be able to redact irrelevant personal information in order to protect custodians’ privacy. That irrelevant personal information rarely shows up in emails, so redacting isn’t a concern to quite the same extent.

Some review platforms support redactions more easily than others. A cumbersome redaction process might not be the end of the world when you’re primarily dealing with emails, but it can seriously hinder progress when there’s a lot of mobile communication and redactions are needed more often.


When there’s a lot of mobile data in your eDiscovery project, it’s important to consider how technology and user behavior shapes this data. This is nowhere near an exhaustive list of the reasons why texting and email are different, but we hope it’s enough to get your wheels turning. What kinds of stumbling blocks have are tripping up your mobile data investigations? Reach out today and let us know!

Curious to know more about how Contact Discovery attacks mobile data investigations? Check out MobileRev™!

Contact Discovery’s MobileRev™ solution turns text messages into near-native images for review

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