No Results in iPhone Mail Search
I support a medium sized law firm and several of the attorneys have reported that their search function for their mail app works inconsistently. I have recently observed that a user can search for a search term and get no results when they have a number of emails containing the search term in their inbox. I have also observed that a user can start the search and see suggested search terms pulled from the subject lines of mail in their inbox and still get no search results. I tested this for one user and performed the same search a number of times. I tried with wifi on and with wifi off. I tried keyword searches and contact searches based off the keywords. I tried the same search 6 times and on the 6th try I got results, then I searched it again after trying a couple of other searches and go no results.
After I updated the users iOS to 9.3.1 I performed all of these searches again and a few more for good measure and all returned results but I gave the device back to the user and it once again returned no results for him when he tried different search terms.
I've observed similar behavior on other phones including my own but since the problem usually goes away I discounted it. I have now seen it enough times on enough different users to think this is probably a bigger problem and people are just not saying anything about it.
How is it possible that the search tool can suggest search terms pulled from the subject lines of emails in the inbox and then return no results when searching for those search terms? How is it possible that I can open an email containing the search term and then when I perform a search for that search term I get no results?
We are using Office 365. These users all have very large mailboxes. I have more than once tried removing the account and re-adding it for a user experiencing this behavior and the problem persisted. I have more than once turned off the phone and back on. I have more than once updated the iOS version on the phone experiencing the issue. The problem is inconsistent enough that most people just live with it but I've heard enough reports at this point to be concerned it could happen in a situation where one of the users NEEDS to find an email and they end up not being able to and at my firm that could be an expensive problem.
Any assistance or explanation of how the mail app could behave this way would be welcome.
Thanks in advance!