The Massachusetts and Nevada PII laws require all email with SSNs or other personally identifying information to be encrypted (TLS or otherwise).

Of the free email providers, GMail does support TLS but they also index the message contents to provide contextual advertising through AdSense.

If we were to recommend our clients of Hotmail (doesn't support TLS) to use GMail, we also want to include instructions on how to opt out of whatever indexing is done within the GMail product.

What procedures need to be followed to ensure that a GMail user's PII data is protected and not published into any index?

  • Hotmail supports SSL/TLS. Can you clarify what you mean?
    – Steve
    Commented Oct 26, 2011 at 18:39
  • Last time I checked a few months ago, Hotmail didn't send me messages via TLS. I assumed this was bidirectional in this case. I should check again. Commented Oct 26, 2011 at 19:02
  • It isn't clear which problem you are trying to solve.
    – curiousguy
    Commented Oct 26, 2011 at 22:15
  • 1
    Not really. The intent of a webmail with huge storage space like Gmail is to keep the emails on "the cloud" (in cleartext), to be able to search them... Why would you even consider using Gmail?
    – curiousguy
    Commented Oct 26, 2011 at 22:41
  • 1
    The simple solution is that using Google Mail to send personal information is not a valid solution. If you are worried about the ability for Google to parse the emails then you must use some other provider that indicates this WILL NOT happen and meet the other qualifications and requirements.
    – Ramhound
    Commented Mar 8, 2012 at 18:11

4 Answers 4


I don't think it is possible to opt-out from Gmail indexing. Also I would expect that emails are not stored encrypted on google server/database.

What you can try to do is to send PII data not in email body but as encrypted attachment (for example password protected PDF or Zip file), that way google will not be able to decrypt it and index it.


  • 4
    "Also I would expect that emails are not stored encrypted on google server/database." Anyway, since Google would handle the encryption key, encryption wouldn't give you much. I still don't understand the question anyway.
    – curiousguy
    Commented Oct 26, 2011 at 22:18
  • I thought that indexing meant shared to 3rd parties... that was a mistake on my part and I updated the question Commented Mar 8, 2012 at 16:56

Social Security / tax numbers should never ever ever be sent by e-mail in plaintext.
It doesn't matter if the E-mail is sent via SSL/TLS, you cannot guarantee that an e-mail will remain encrypted throughout it's life. (You can almost guarantee that it won't be)

I don't know what "personally identifying information" really means, but absolutely no information that could be use for identity theft should be included in an e-mail.

  1. No CC numbers.
  2. No SSN/TID.
  3. No "security question" answers. (mother's maiden name and the likes)
  4. Driver's license number
  5. etc.

If you absolutely must send this information by e-mail it should be in an encrypted attachment.

  • 1
    Although I agree with this in theory, it doesn't work for all business process in reality. Sometimes normal end users are conducting a business transaction by email and can't (won't) work with encrypted blobs. In addition, I don't take responsibility for an email throughout its life, its only within my borders. I'm not my brother's keeper, though I will support an encrypted payload as you describe. Unfortunately some customers have mobile devices or use a web client that don't support SMIME, or various other encryption schemes. Commented Oct 26, 2011 at 17:31
  • One more thing, some email partners prohibit encrypted payloads if they are supervised by law, or financial regulations (Smarsh) Commented Oct 26, 2011 at 17:34
  • Why do normal end users need to see the pieces of information I referenced? And they made prohibit encrypted payloads.. but you're not suppose to be sending this type of information by e-mail at all.
    – user606723
    Commented Oct 26, 2011 at 17:54
  • Signed copies of Life insurance forms include HIPPA PII as an example. Other industries have different practices and needs Commented Oct 26, 2011 at 18:03
  • 3
    Is there a reason you can't simply include a link to the document which will be downloaded over ssl?
    – user606723
    Commented Oct 26, 2011 at 18:37

how to opt out of whatever indexing is done within the GMail product

Gmail and most other modern webmail systems are built around indexing. There is no way to prevent the mail service provider from indexing your email.

Even if your users were able to opt-out of each feature, to avoid indexing they would have to opt out of core features including search and spam filtering. They would also have to opt out of marginal features such as automatic translation.

Could you provide some background on why indexing presents a threat to PII in your scenario? Would you agree that if an index is

  1. stored within the same privacy cordon as the raw content (for example, subject to the same encryption on disk and readable only by the same principles)
  2. can only be accessed with the same keys/credentials as the raw content
  3. does not outlive the raw content

it does not, by itself, increase your risk of PII exposure.

  • For some reason I wrote "indexing" when I meant share to 3rd parties. For some reason I thought they were the same thing. Commented Mar 8, 2012 at 16:55
  • @makerofthings7, I understood indexing to mean creating an internal table mapping words to documents that contain them. Indexing: "The indexing stage will scan the text of all the documents and build a list of search terms, often called an index, but more correctly named a concordance. In the search stage, when performing a specific query, only the index is referenced rather than the text of the original documents." Commented Mar 8, 2012 at 17:29

If you want Personally Identifiable Information to remain private, then you can't put it on the Internet. Really, that's the only way.

The laws you mentioned are something of a nonsencial visceral reaction to the recent privacy media scare, and aren't really a reflection of security, reality, or sensible policy.

Instead, if you don't want your name to be made public through Gmail, then don't give Gmail your real name. If you don't want your email address to be public, then don't use email -- because in the very act of using it, you're publicizing it, and it will be indexed somewhere; either by Google, Yahoo, Yandex, Lycos, or any one of dozens of public data repositories.

Now, I'm not saying ,"you have no privacy, get over it." Instead I'm saying that if you interact in a public medium, you can't expect everyone to forget who you are. You can have privacy as long as you are meticulous about not sharing any information that you want to keep private.

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