Q: how to stop frequent keychain login password requests

This problem is very irritating, I’m getting asked frequently by OS X to enter a keychain login password.  What I’ve read suggests this is related to a problem with Keychain Access.  One explanation says it can be caused by an administrator account password change where the default keychain password does not change, resulting in an inconsistency.  I have NOT changed my account password so I don’t think this is the cause of my problem.

I’ve also tried using Keychain Access First Aid, but it currently finds no problems.

In my case, this appears to have started after an upgrade from OS X Mavericks to Yosemite.  When I did the upgrade, the first problem I encountered was Mail stopped working – I was unable to send or receive mail.  I could, however, go to my mail provider at their web site and view mail there just fine.  That problem was resolved by using Keychain Access First Aid - I can now use Apple Mail on my "Air" just fine, but I’m still being inundated with frequent requests to enter a keychain login password.  I get these requests from Mail, AddressBookSourceSync, Messages Agent, Safari, Local Items, CalendarAgent, and com.apple.MailServiceAgent.xpc. 

Once I enter my login password to 3-5 of these requests, I’m able to continue working on my Macbook Air, however once I close and reopen the lid of my Air, the requests start anew.

Any help would be greatly appreciated.  Thanks.