Over the last few weeks, I have had people saying they see emails on their phone but not on their desktop.
I find that Webmail, IMAP, MAPI, EAS all show a different sets of emails. IMAP/Web Mail show the most, but EWS shows some that are missing from both IMAP/Web Mail. MAPI shows the least amount of emails. MAPI, EWS and EAS all show a different set of emails (i.e., each protocol has various emails missing). IMAP and Web Mail seem to be identical to each other.
If I remove and re-add an account using EWS, a totally different set of emails show up than before I removed and re-added the account. I can replicate the EWS, IMAP, Web Mail differences using eM Client 9.x. I'm using Outlook 2016 for MAPI.
I've already re-indexed the users which doesn't seem to change anything. The reports are coming from multiple users. It started in JULY 2024!!!