Emails disappear after looking at them in Mail

Beccer-Tree wrote:

I do not know were this filter is.

The filter switch is at the right above the column of messages.

The green disk surrounding the three white lines indicates a filter is active. The text "Filter by: Unread:" shows the nature of the filter. Click on the disk to switch the filter off and on. Click-and-hold to set other options of the filter.

Beccer-Tree wrote:

New. I am using Proton mail. I have been using them for a long time. About a month ago things started disappearing. Before that there was no issue. I updated the operating system to see if that would help. Id did not.

well Proton is known to be problematic. ref Contact Proton support

see raving reviews——

"Temporary? This is an on going issue. I have been having problems even sending email for ... Years. I even have the paid account because even after I cleared my mailbox it still said it was full. Your system is seriously ******. Every other day there is a problem. I just haven't had time to change EVERYTHING over to a different service. Proton mail is hands down the most problematic email service I have ever used.”

ref:https://www.reddit.com/r/ProtonMail/comments/bgs6vy/protonmail_down_incoming_emails_are_not_getting/

However for your issue— if local Mail.app—

problem accounts the go to way to sort an issue like yours—simply remove the account and add it back in and see if it resolves. If not Proton is your best way forward for support...

Remove email accounts in Mail on Mac

Remove email accounts in Mail on Mac - Apple Support

Add email accounts in Mail on Mac - Apple Support

Add email accounts in Mail on Mac - Apple Support

Note—

IMAP accounts stay on the server, so no local loss, when you re-sync

POP accounts download and remove from the server—therefor save your inbox/sent box if you want them

On My Mac" is just that, local folders you created and moved mail into. So no loss

Beccer-Tree wrote:

I have a email internet email account set up in mail. After looking at the email they disappear. Many I would like to find again and must go on line to do so instead of just going to thee mail app.

hmmm...Seems odd.

Old issue, new issue, what changed?

Is this IMAP or POP account.

Who is your email provider?

Beccer-Tree wrote:

New. I am using Proton mail. I have been using them for a long time. About a month ago things started disappearing. Before that there was no issue. I updated the operating system to see if that would help. Id did not.

Log into your email account using the email provider's webmail page. Are the emails there?

Beccer-Tree wrote:

Thanks for you input. I love my proton account

I was hoping to hear more your results— after you removed and added back in the account as suggest above in an effort to resolve your issue...?

Did you by any chance accidentally enable the filter to display only unread messages?