Hi @CLAUDIA CASTRO ,
What type of account are you using?
Does the issue also exist on the web?
In order to avoid the influence of the old version, it is recommended you check the version and upgrade it to the latest:
In Outlook, go to click File > Office Account > Update Options > Update Now
If that doesn't help, it is recommended you create a new profile and re-add your account:
Go to Control panel > Mail > Show Profiles > Add, then re-connect your account.
Hope above suggestions may help you.
If you still need help on this, feel free to contact us.
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