For 2 years I received all mails from a no reply e mail. One of our service providers. Last two weeks - nothing. Have done all junk settings. Nothing works

For 2 years I received all e mails from a no reply e mail address. These e mail come through from our service provider. For 2 weeks I can not get these e mails. The e mail address was always in my address book. I have removed all junk filters, disabled adaptive junk filter junk filter logging and reset training data. Still no e mails. Our IT have also checked and there is nothing set to block any emails. It is really frustrating and effecting our business. Please help.