E-mails Never Arrive (possibly blocked by Barracuda/spam filter?)

Long story short -- certain e-mails appear to get "black holed" for me. I'm guessing they're getting caught up in the Barracuda or whatever device being used -- and they're never getting released. This has been going on for about 2 years now and I've been trying to get it resolved for at least 6 months but don't seem to get anywhere.

It has gotten to the point that there are multiple accounts I cannot login to for various reasons, IE: two factor authentication e-mails never arrive. Today a site is forcing me to change my password to my account, by sending an e-mail to me (because the site was breached) -- but those e-mails are not arriving like many others -- effectively locking me out of that account -- because of this issue.

This all started after I accidentally selected all my email on my iPhone, and designated it as junk. I went through and restored the e-mail -- but ever since that day, e-mails do not come in from many senders. I don't know how that could have caused it, but it seems to be connected. Also -- it does not go into my spam folder -- it never arrives in any way shape or form -- and it happens to at least 10-15 different senders. I've slowly changed my accounts over to my Gmail account because of this issue, but some accounts I cannot access to do this. It does not matter what client I use, the e-mail never arrives.