I can’t say a lot, it was pretty much a chat with the support assistant of my hosting and domain provider.
I told them the whole situation and I was very specific that my problem was my domain, that my WordPress hadn’t problems to send emails to any other addresses, only mine.
After a lot of waiting time they just told me to do another test and finally worked.
After two hours in support line with my provider finally the problem has been solved. I’m gonna mark this as resolved. Thanks!
Sadly no, the Check & Log Email plugin don’t give me any error messages, only this:
“The test email has been sent by WordPress. Please note this does NOT mean it has been delivered.”
But I know the emails are not reaching my mail because the process is instantaneous. I make a test with a gmail address and by the time I check my phone the email is already there.
I’m gonna check this situation with my hosting provider again expecting a different result this time.