Please check your spam and junk folders. Every once in a while, Outlook (or whatever applicable mail client you use) will notice that an email from a particular address will repeatedly be sent. Outlook, not knowing if this email is “trusted” or spam, will just spam it.
If you see it in the spam folder, you can move it to the inbox and create a new rule to set it as “never spam.” Which, interestingly enough, needs to be updated now and again.
Other than this, what can happen, if you put in an email address in that field of the software that doesn’t exist, it’ll block the email automatically. This is much rarer, as Partners usually have these emails setup beforehand, but it does happen.