mail disappearing after one month

[Jeannie]

So I finally upgraded and got a desktop computer with sonoma.
I still have my old desktop with el capitan...as it works well for 'its age' (if you don't mind a few beachballs once in a while)
On my sonoma....email disappears from my inbox after 30 days...whereas with the el capitan, email stays in the inbox until I delete it. So there is nothing wrong with my email provider...shaw-rogers.
The only difference is mail set up for sonoma....is imap ( it did it automatically when I was setting up....I think) ...whereas el capitan is pop 3.
Would that be the reason for how mail stays in the inbox? I have tried looking into settings on my sonoma mac to not delete email from the inbox but I can't see a setting to change this.
How do I stop mail disappearing after 30 days?

 

[DaveWT]

Sorry, I don't have the solution for you, but to help someone else help you with this, a few questions...
What mail app are you using? Apple Mail or something else?
What is your email account? iCloud? gmail? something else?

 

[Jeannie]

apple mail
shaw

I still have my other mac working .. receiving and keeping all emails ...until I delete. It uses the pop 3 setting.
So I am puzzled why the new mac (...it uses Imap setting )doesn't keep mail and after 30 days and now I noticed when I delete email on my new mac...it appears to disappear...I can't find it in the delete folder or the trash folder....

 

[chas_m]

POP = Mail is stored on your machine, so Shaw doesn’t have it anymore.

IMAP = Mail stays on Shaw’s server, status (read, deleted, etc) is synced across all your devices.

Mixing POP and IMAP access across devices = great way to lose mail you wanted to save.

I would STRONGLY recommend copying any email you want to keep to local “On My Mac” folders, then deleting your POP Shaw account and adding it back in as an IMAP account so all your devices are using IMAP going forward.

And do not expect that Shaw email account to be around for much longer.