Missing Mail And Photos


I have a problem with Mail and iPhoto. After opening Mail first thing one morning I notice the latest messages that were there the previous day were missing from the Inbox. I used Time Machine to restore the previous day (I think I did it correctly - it said restoring over 7xxx MB) but the messages I expected still did not show up. I haven't try earlier dates yet.
Next, I loaded several photos and they imported into Photos normally. I also imported them into iPhoto but noticed that the last event in iPhoto was from 2012. I have imported photos into iPhoto every month for years with no problem. I'm not sure how to see if the missing photos are restorable withTime Machine.
Could an automatic OSX update have caused the problem?
About this Mac shows I am running 10.11.6 on a mid 2011 iMac with 12 GB memory.
I did check and just tried again after your reply, but there are only a very few photos there.
They are only some of the ones the Photos application on my Mac show. In any case I was looking for photos that I still keep in iPhoto.
Do you remember what you did right before you discovered the missing photos and emails? Did you update/upgrade? Did you turn off iCloud? Do you have more than one email account in Mail and you turned off or deleted one?
No manual update, possibly automatic update?
No problem now, I recovered everything from Time Machine and re-imported the photos since that backup.
Thanks for all your replies.
Do not rely on Time Machine for your future backups. Get another external drive and use Carbon Copy or Super Duper to do a total back up of your drive. Do it once a month - say after you import your photos. Then you will have a secondary back up and no worries.