I would like to point out that the app is present on the playstore but only distributed locally.
In the App there is a function to send a log via email with a gmail account, how can I protect the password?
I wanted to add that the app is installed on phones with multi-operator data SIMs that are not enabled to send text messages
Storing the password inside the app doesn't seem like a good idea. Maybe go with an web service to receive the logs and then forward them to your email account if necessary. Requires more work but won't leak your password.