Here are some things you can try if your emails are disappearing on your Samsung phone:
Check your internet connection: Make sure you're connected to Wi-Fi or mobile data.
Remove and re-add your email account: This can help fix minor issues.
Check your auto-delete settings: You can set your email to automatically delete messages older than a specified number of days.
Check your email folders: Emails might be in your Spam, Trash, or Archive folder. Messages in the Spam or Trash folder are permanently deleted after 30 days.
Check your email filters: Filters can move emails to unexpected folders. You can edit, delete, or create new filters in your settings.
Check your forwarding addresses: Emails might have been forwarded to a different email address. You can check your forwarding addresses in your settings.
Contact your email service provider: You can contact your email service provider for help.