A couple of questions.
When the mail disappears from the phone, are they still avaliable on the Mac?
There is a setting in; Settings>Mail,Contacts,Calendars - Mail - Show ## Recent messages.
How many messages are set to show?
Is you mail POP or IMAP? If IMAP, any messages that you manually delete from the phone, will also be deleted on the Mac as you are deleting from the mail server.
Thank you for your quick response!
Yes, they are still available on the Mac. They just disappear on my phone and I can't find them anywhere, they don't simply go to the trash folder.
It is set to 'Show 1000 recent messages', but for now I have only 4 messages in my inbox (I like to keep only my important mails on my phone, and since I'm a student, I don't get too many important mails).
My Mail app on my Mac says my hotmail account is a POP account.
I'm by means no expert with Hotmail, so others here my have better suggestions.
I'm firstly presuming the settings on the Mac and phone are correct.
There is a setting on the Hotmail web site, that I think you should check.
Log into hotmail using your web browser.
Go to settings>more mail settings.
Under Managing your account>POP and deleting downloaded messages.
Make sure "Don't let another program delete messages from Outlook" setting is checked.