Looks like my jr domain Mailgun acct was hacked
Using Jamroom
So- in retrospect, several RED FLAGS to look out for as a hacker is working their way into your mailgun account:
1- getting emails from a Mailgun support person saying your domain needs to be validated... even though your domains are already validated. I ignored these emails thinking they were from a spammer.. but they were perhaps indicative of the hacker being in the process of infiltrating my account.
2- getting a support email from Mailgun responding to a support ticket request that you supposedly made, asking for a new Dedicated IP on your account. Big red flag!! This support ticket was actually created in my mailgun account by the hacker, and you must immediately contact Mailgun support and report this as a hacker.
3- getting a friendly note from mailgun suggesting you might want to 'upgrade' your account to higher capacity... this was sent to me about a day after the 2 million spam emails had been sent out by the hacker. =8-o
And it's always wise to glance at your mailgun LOG each day for each domain, so that you can see within 24 hours whether a giant mountain of spam has been sent out. Note that these spam emails did not show up on my Jamroom email log... only in my Mailgun account Logs, on the MG site.
My notifications seem to be turned on again and working normally, so I'm going to mark this thread as a "User Tip". Hopefully it will be of some use to somebody else at some point.
updated by @strumelia: 06/24/18 11:31:54AM