My sent and trash mailboxes suddenly emptied. I can send and receive mails but the sent mails also vanish. Where did everything go? What is wrong?
This may have happened due to a eg: another device computer or mobile that is configured to your same account has possibly deleted them and eM Client would then just mirror your mailbox to show the same, or Alt could be some sort of issue has happened to your account in eM Client locally.
Do you have an IMAP, Exchange, iCloud or POP account ?
If you go online to your webmail, are the sent and trash mails there ? If the emails are all showing ok online and you have an IMAP, Exchange, iCloud acct, then suggest to just remove and re-add your account which will normally automatically bring back all your emails to match your online emails.
If your emails (are not showing online) as you have a POP account, then your only option would be to try restoring an eM Client backup or recent computer image if you have no eM Client backup…
To restore a backup if you have been making either automatic eM Client Backups via “Menu / Settings / General / Backup” or Manual backups via “Menu / Backup”, you can restore via “Menu / File / Restore”.