First, Just so there is no misunderstanding, this is a public user-to-user support forum. We're users just like you helping other users. We do not work for Microsoft.
As for trusting you, absolutely do, have seen too many reports lately from different people all reporting the same thing. As I said, the current Junk filter is broken, As for anyone manually looking at this? Doubt it given the millions (billions?) of junk messages floating around at any given time.
You are also not going to get me trying to defend the situation - the current situation "sucks" and there is really no nice way of putting it.
In regard to
>>
same sender (each day), same format, from different company, same sort of text.
<<
One thing I might suggest is creating an <Inbox> rule using the following settings - not as some kind of permanent solution but simply as a possible way to reduce the aggravation
Condition: <Message header includes>
Value: ***whatever value you are looking for***
Action: <Delete>
Use inbox rules in Outlook.com
https://support.office.com/en-us/article/use-in...
This link will bring you to the <Inbox> rules
https://outlook.live.com/mail/0/options/mail/rules
Without taking anything away from what you have said, please indulge me with the following standard reply I give to those who ask about a sudden increase in <spam> and <unexpected> log in attempts describing how email addresses are harvested which you may find of interest. I can tell you that I have multiple Outlook.com email accounts and not one ever gets any spam (and I do mean <never>). Unfortunately I can't say the same for a couple of other non-Microsoft email addresses I use which get a boatload of crap every day - just a fact of life.
The usual source of a sudden increase in failed login attempts or spam mail received is that the email address was harvested by a hacker who breached a data base on a website where you subscribed to something. That database gets repeatedly sold to other hackers/spammers on the dark web.
Many people think that hackers penetrate the actual Microsoft servers to gain access to email accounts when that isn't the case. Instead they gain access to an actual account via any number of other ways including phishing emails.
You can check to see if the email address comes up on a breached database on the following website created/run by Microsoft MVP Troy Hunt.
https://haveibeenpwned.com/
Pwned websites
https://haveibeenpwned.com/PwnedWebsites#Epik
Other articles that may be of interest
The 773 Million Record "Collection #1" Data Breach
https://www.troyhunt.com/the-773-million-record...
How Do Spammers Get My Email Address?
https://www.lifewire.com/how-do-spammers-get-my...
Protect your privacy on the internet
https://support.microsoft.com/en-us/help/409145...
Protect yourself from phishing
https://support.microsoft.com/en-us/windows/pro...
*** if you find that the email address was on a breached website where a password was also entered, what you really do want to do is make sure that the same email address/password combination is NOT being used on other sites (i.e. Social Media, Facebook, Paypal, Amazon etc) and if that password is still the one being used on your email account - make sure to change it immediately. Not a question of <IF> a hacker will test those account(s) - just a matter of <WHEN>
Required Forum Disclaimer: Some of the above links are non-Microsoft websites. The pages appear to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.