I'm finding that random emails disappear, from Outlook and/or webmail but will arrive (and stay) on my phone (via EWS). Right now I have an email which was sent to me and two other accounts, all of which (the sender and the recipients) are hosted on the same SmarterMail server -- everyone has received the email, including my iphone except that I cannot see it in webmail or on my email client.
This particular email was send this morning and there is no way it was deleted - it popped up on my phone a few minutes before I checked by email client, and anyway if it was deleted I'd expect it to disappear from all devices.
I have two customers who have reported the similar problems, and I have had this in the past. Previously I had assumed that it was a problem with Outlook clients, but my desktop client now is an IMAP client (not Outlook)
What's going on?
I'm using SmarterMail Version 14.5.5871, my client is AirMail v2 but previously experienced problems with Outlook 2016 using EWS and IMAP, and customers have complained using Outlook 2011 (on Mac) with IMAP. My iPhone is using the Exchange connector.