There are no known issues like this.  Might want to contact support so we can look at the server.

Tim

Would I be able to downgrade to build 7642 from 7669 without any issues?

Thank You

Yes, but if you are seeing that problem then it probably has something to do with the data on disk and the previous version would show the same results.  Maybe you have a client that is removing or modifying these messages etc?  Please contact support so we can verify things for you.

We start to see this issue as well on 2 servers. Some customers were reporting this problem today and just now it happened on my own mailbox as well. All sent-items emails of today are gone only 3 are left! We will revert back to build 7619 tonight.

I only use webmail and EAS to access my mailbox.

I went back to build 7611, thats what I was on before not 7642.  I saw that the files were still on the server when I looked in the sent items. I removed the cfg file in the mail box. Restarted the server, then login in as admin and reindexed and waited over night This morning I logged in as the person and check the sent folder everything was there. So far so good. He is still missing a couple of emails (I think they were corrupt).  

He uses webmail, outlook and the apple email app.  I had him remove the apple email app last night before I deleted the one file and reindexed his mailbox.  I don't know if it was the apple email app or the roll back to the older build.  I'm gonna check this out all night fir him.  Tomorrow if everything is fine I'm going to have him download Outlook for his iPhone and hopefully everything will be fine..

We are aware of an issue now.  We have a couple customers seeing the same issue.  The messages are in the Sent Items but how we are parsing the .CFG for some reason is ignoring them.  Its very rare but it is occurring and now we have customer data to evaluate. If you are seeing the issue, please open a ticket with support.  We just have a couple of tickets on it and could use more customer installations to evaluate.

We just received a report of this issue today. I can see the missing sent messages in the domains archive. Also as Jim pointed out the messages are present on the server in the grp file. As a temporary fix I was able to remove the Mailbox.cfg file and then rebuild the Sent Items folder to get the messages back for the user. I'll open a ticket so support can take a look.