Older emails not visible

I’ve been using eM Client for almost two years now with no problems, always on the same computer. Recently I’ve noticed that I can’t seem to see most of my older e-mails. Something that has not been a problem before. I can find the 5-6 most recent e-mails in the “inbox”, and a few more in “sent” and “drafts”. But dozens of older e-mails are entirely missing. Also if I try searching for them by the titles (they are all only five letter titles so they should be easy to find) nothing shows up, even if I have ticked the box for “download messages for offline use” in IMAP.
I use my e-mail for business daily so I really need to find these e-mails. Any solutions?

If you login to your email account using the web interface of your provider, can you see the missing messages?

Best option though, as a Pro License user is to open a support ticket with eM Client. They will be able to assist you further either by email, or by accessing your computer remotely with TeamViewer if necessary.

Save your mails is the saviest way to refind them.
And a good Backup program as Nero and Carbonite can resolve your complaint.

Applications like Carbonite do not work with eM Client. All you end up with is a server directory full of empty files.