I'm experiencing an issue with the "Recent Conversations" feature in the "Messages" tool (My Profile > Messages > Message Navigation dropdown: Recent Conversations). If I do a test (see details below), and create for example, 10 recent conversations with my admin user and 10 other different users, within 4 or 5 days (and sometimes sooner), some messages "disappear." I don't see a specific reason why certain messages disappear.

I've noticed, by doing further research, that the query that pulls the messages to the "Recent Conversations" has nothing to do with a time limit. So messages aren't being removed after a certain # of days. It also appears that the "Recent Conversations" area is limited to 100 conversations by default.

None of the users in my testing have been deleted. I understand that deleted users would make a recent conversation disappear, but that's not the case.

• Brief Description: Messages are being removed from the "Recent Conversations" area for some reason, and it doesn't have to do with: a user being deleted, I'm not sending a message to myself, and the notification field in the message_read table is not something other than 0. I'm trying to determine how and why messages are being removed from the "Recent Conversations" area.

Steps to Replicate:
1) As my admin user, in a browser such as Chrome, go to my sandbox environment and login with my admin account.
2) As another user, login to my sandbox environment using Firefox, and go to My Profile > Messages > under Message Navigation go to Contacts > search for Michael Chynoweth > add as a contact and then send a message.
3) Back to my Chrome browser and my admin account, navigate away from the Messages area, and back to it, and click on Recent Conversations, and see that the message from the 2nd user (on FF) appears. Read the conversation as the admin (or any other user).
4) Complete this test and steps 2 and 3 above with 10 other users, so the admin has a large number of recent conversations.
5) Give it one day (or many days), and log back in and see how many conversations show up in the recent conversations area. As you can see in steps 3, 4, 5 and 6 below in the "Troubleshooting Steps Performed area" there are mixed results.

• Expected Result: Conversations between two people should show in the Recent Conversations area, and users should know when to expect a conversation to "drop-off" from the recent conversations.

• Actual Result: It seems as though conversations in the Recent Conversations area "disappear" without reason, and we can't explain why.

Troubleshooting Steps Performed
1) I searched in Google for: docs.moodle.org and forums and recent conversation and found a discussion that talks about what table the recent conversations pulls from, but as those two users talk about, they're not sure how the "Recent Conversations" area works. See this link: https://moodle.org/mod/forum/discuss.php?d=276092

2) I searched in tracker.moodle.org for Recent Conversations and found an Enhancement: https://tracker.moodle.org/browse/MDL-26218, but it's not the same issue.

3) I created 11 conversations in my mchynoweth sandbox on Thurs, 6/4/15, between an admin and 11 users (one student: rsandberg; and one instructor: lsmith, and so on - see screenshot: http://screencast.com/t/aTeSbDOO12). I saw these conversations in the "Recent Conversations" area here: http://screencast.com/t/PIODSsrRsMU. With that being said, based on the discussion above, I queried the (select * from mdl_message_read select * from mdl_message_read) Table and I saw the recent conversations there. So far, with 11 conversations, none have dropped off.

4) When I went into the "Recent Conversations" on 6/5/15 (after seeing 11 conversations on Thurs, 6/4), now I can only see 9 recent conversations. See screenshot: http://screencast.com/t/g7y4NfSX

5) Next, for one of the students who I sent my admin account a message to, and whose message disappeared on 6/5/15 (rsandberg), I logged back in with my rsandberg account and sent a message and it appeared in the Recent Conversations area for my Michael Chynoweth account, so it's now showing 10 recent conversations. http://screencast.com/t/LD83bowjqek

6) Then, 3 days later, on Monday (6/8/15), I logged in with the Admin user, and I could see the 10 recent conversations messages that I saw on Friday. So two messages "disappeared" from 6/4 to 6/5, but none "disappeared" from 6/5 to 6/8.

7) The last part of my testing, involved waiting until Tuesday, 6/9/15. In doing that, this morning (Tues - 6/9), I see only 8 messages. So two "disappeared" - two that disappeared weren't the two oldest messages. See screenshot of side-by-side comparison of Monday and Tuesday "Recent Conversations": http://screencast.com/t/izZZxUS4T