We are trying to develop a new software product that requires an integrated email client. We found some old patents from Google regarding email systems.

https://patents.google.com/patent/US9819624B2/en https://patents.google.com/patent/US7818378B2/en https://patents.google.com/patent/US7912904B2 https://patents.google.com/patent/US8150924B2/en

We are trying to understand whether creating an email client similar to Gmail (with conversation threads and labels) will get us into trouble with Google later on. Yahoo Mail is a similar product to Gmail, for example. We are not sure to what extent having conversation threads in an email client is patented.

How can we avoid a legal conflict with Google, considering that we want to create a better product, not worse ?

  • 1
    The last linked document is an application. It has been issued as patents.google.com/patent/US8150924B2/en. It's important to link to actual patents as the claims might be significantly different.
    – Eric S
    Jan 16, 2019 at 15:19
  • Thanks for pointing that out. I am still learning about these patent differences.
    – Morco
    Jan 17, 2019 at 9:32

2 Answers 2


The standard answer is to engage an attorney to do a freedom to operate search and give you a written opinion. This presupposes that you know what you are building and how it works in some detail. The search would look for patents that are in force that have claims that look like they might cover what you are building.

Since you are in the early stages of development you might consider a "design-around" exercise. That involves identifying problematic patents, studying their claims (with professional help) and figuring out a way to accomplish the end you want without using the specific means to that end covered by the claims. One angle you might take is to look for things that came before - for example - the last google patent mentioned. Something listed in the google patent that came before the google patent is --

US5832502A 1996-07-02 1998-11-03
Microsoft Corporation Conversation index builder

Anything filed in 1996 will be long expired. Can you do what Microsoft did and not do what google has claimed? Of course this is just one of the several patents you located.


You might do the same for other references listed on each of the google patents. It is a lot of work. One way to narrow it might be to decide that your biggest worry are patents on something core to your value added that are owned by your biggest competitors.

  • You might want to mention that a good technique is to look at the cited prior art in the Google patents. Then the cited prior art to the most relevant patents, etc.
    – Eric S
    Jan 16, 2019 at 23:47
  • This sounds like a lot of "dig in" work with a significant budget required. We were hoping to find some "shortcuts" or safe approaches to this. The idea of looking at expired patents or prior art and going from there might be useful. Thanks.
    – Morco
    Jan 17, 2019 at 9:40
  • @Morco You can read the patents yourself. The important thing to remember is that to infringe on a claim, you need to implement each and every step of the claim. Long claims are therefore narrower and easier to avoid infringing. If there is some patent that you can’t design around, there is always the option of licensing.
    – Eric S
    Jan 17, 2019 at 13:41
  • I would also add that if doing a patent analysis then safer to have attorney opinion since you have already looked at the patents else steer clear of patent study. Pointers - Halo risk, Willful Infringement. On the other hand, this is a very crowded tech space and if not these patent claims there may be others & therefore no easy way to ensure that you are not infringing any patent. And as a future defensive tool file few strong patents on key tech in your product.
    – iktaara
    Jan 18, 2019 at 5:53

While a freedom to operate opinion from an attorney is best, you can do some of the work yourself. You made a good start identifying the specific Google patents. You need to read the claims to see what is protected by each of them. In order to infringe upon a patent, you need to implement each and every step in at least one claim. Long and complicated claims are easier to circumvent as you only need to avoid a single aspect. Focus on the independent claims first. Independent claims don't refer to other claims. Each patent will cite other patents as prior art. Look at the prior art especially for older patents where the priority date is more than 20 years ago. Those patents should have expired by now (sometimes there are short extensions if the patent took a long time to process). Anything described in an expired patent's claims should be available to use.

Generally I read patents by looking at the claims first and then reviewing the body of the patent if I need help understanding the claims. This way you can weed out irrelevant patents quickly. By doing this work first, you can then make an interaction with a patent attorney much more efficient and thus less expensive.

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