My wife and I have experienced the same issue. Today using Outlook in a web browser and found old messages that did not appear in eM Client ver. 10.3.2619. Have not encountered any problems with Gmail.
Hi Callisto,
Is it possible you have a rule or junk mail filter in eM Client? Or perhaps you have different views between the webmail and eM Client versions (e.g. handling of threads/conversations)?
You might possibly then have eg: Categories enabled and the missing emails are in other Inbox Tabs. See the following eM Client Blog.
Now if your Outlook emails online are not in a Category Inbox Tab, then you might have possibly accidentally moved them to another eM Client account mail folder in which case try doing a Search for them in All Folders as per below.
Go to the search field at the top centre, and select “All Folders” in the dropdown field, and then type a search for text that you know is in the Subject or Body of those emails and see if any of those emails then appear.
“eM Client Search documentation”
https://www.emclient.com/webdocumentation/en/10.0/emclient/default.htm#Getting%20Started/Search.htm
After much exploration was able to see the missing mail in Outlook.
Settings > General > Folders > Checked Inboxes and the sub folders under Favorites. Thank you for your help.
An update to my solution, forgot to add one more step.
General > Mail > Categories > uncheck the box “Show Categories”.
