Hey! Long time not using Windows, I tried eM for mail.
Unfortunately, your software suffers to a problem I find on couple other clients.
My Gmail account is pretty large, created at the very beginning (when there were invitations :).
eM seem to synchronize mailbox starting from oldest messages, and as you may guess, it may take a while, to sync 10+ years of correspondence.
Yes, I have found fascinating photos I shared a long time ago, but this is not necessarily a benefit I was looking for
The other client, I use on Mac, which is my favorite now, starts from the newest mail, and does the hard job silently in the background. But at the start, I see my recent mail and can use it.