Welcome to Justanswer.com, my name is Dustin.I'm sorry to hear about the issue you are having, I will do my best to help you resolve it.
You had never previously accessed your optimum email through your macs mail app?
Just to be thorough, go ahead and launch mac mail from your mac. Maybe theres some of your optimum mail inbox, there.
Let me know what you see or find.
Theres no need to log out of her mail.
Your mail and her mail could have been there at the same time if you had tried to setup your optimum mail on mac mail even once..
So let me ask this.. Even on the optimum server online, if you log in directly w ith a web browser, your inbox is completely empty?
Had you connected any new devices to your mail account recently?
Or accessed your mail from a different phone or computer?
Or from public wifi?
Allright, I want to be forthcoming and straightforward with you. As far as the missing emails. Since you never accessed your mail through an email client, such as mac mail, thunderbird, outlook 2011 / 2016/ etc..
There isnt a hard copy backup of your email that we can restore. You went to the only place that could help you with those missing inbox emails, optimum.. And hopefully they will help you restore them.
All that I can do for you is either
A. I can help you setup your mail account with an email client, so in the future you have a hard copy of your emails in case your online mail server gets cleared out. Also, I could help you check your phone and mac and make sure you didnt pick up any spyware or malware when you were on public wifi that may have allowed someone to access your mail account.
Or B. I can send you the refund link now if you dont want to do step A, as considering the specifics of your situation as we discussed it, I cannot help you recover the mail. There simply isnt any way to do so other then through optimum.
Absolutely, here is the link in question.
And believe me, if there was any chance to recover your messages. Even a fringe chance, Id help you go over it. Going forward, I would strongly suggest that you setup a mail client on your computer to access your mail through, that way if your mail ever does disappear again, you have a copy on your computer you can refer to if needed.
Best of luck to you,