I have an ongoing issue where my IMAP mailbox does not sychronize. New mail messages do not appear in my inbox, even if I manually do a “Send and Receive All”. If I exit and restart eM Client they appear as expected, and I usually get a few more new emails then have to again restart the program to get all of them. I think this may be related to use of email clients on other platforms (Gmail on my phone; Thunderbird on another PC) but doesn’t IMAP support multiple clients accessing the same mailbox? I never had this issue with other mail clients.
On what is perhaps a related note, often when I attempt to read an email that IS in my mailbox, I get a message saying that the message wasn’t downloaded and to click a link to do so. When I do that, I get another message saying that it will be downloaded “the next time I am online”. Annoying, since the PC *is* online the whole time … but see above.