resource mailbox?

Question

Hi. I work for Aldi UK and am trying to receive an email from them to download my app for work. this app is really important as it allows me to access pay slips, view my rota and lots of other crucial things for work. They are trying to send me an email with a link to access the app and i am not receiving the email. I have been all into my settings, made sure they are not a blocked contact, added them to my safe senders list and still nothing. When receiving an email from them, their sender name is coming up in red and says "res mailbox" I have googled and this means resource mailbox? I am wondering how to access this and if this is the problem? or are their emails being bounced back? I am receiving normal emails from them, but anything with the link to pair my device, is not coming through. I am really getting frustrated with this and need it sorting ASAP. Is there anything you can recommend or help with? Thanks. Amie