we have a business requirement to change the minimum number of characters from 4 to 3 (or even 2) when searching GAL from ActiveSyn

You may have a business requirement for it - but it isn't possible to change the behaviour of the clients.

Simon.

Exchange 2007 and 2010 it's do manually but I can't change in exchange 2013. Anybody can be give process for change 4 to 3? 

Hi Md,

Please share the steps or the link for Exchange 2007 and 2010, it will be easier to check.

Hi Ramin,

Open C:\Program Files\Microsoft\Exchange Server\V15\ClientAccess\Sync\Web.Config

Add this before </appSettings> like this:

<add key="CAS_MaxTimeInMinutes" value="720" />

<!-- Sets the minimum number of characters required for searching --> 

<add key="MinGALSearchLength" value="2"></add> 

</appSettings> 

Open Cmd.exe IISReset [Note this will disconnect live users in production]

References:

How to Query Minimum Gal Search Size:
https://social.msdn.microsoft.com/Forums/en-US/a59466dd-9bbe-4549-a7bb-7a01bc7f8635/how-to-query-minimum-gal-search-size?forum=os_exchangeprotocols

Error:SearchStringTooShort - Solution edit the web.config file on all of the CAS servers:
http://terenceluk.blogspot.in/2013/12/unable-to-search-gal-with-less-than-4.html

Hi,

Have you tried the above solution, please let us know if you have anything else that works.