Not receiving emails from FTH

this is for 6193.toastmastersclubs.org/ and I'm logged in as the administrator.
I'm using FF 45.0.2

for some reason, my husband and I are the only ones not receiving the emails. I checked to see if you are spam listed. And you're not (woohoo) Then I also called my hosting company. but your messages are not even going to my host server. (much less my MS Outlook)

I've looked at a few other tickets that similar problems and there seem to be a setting on your end that needed to be fixed.

Here are the two other links.
support.toastmastersclubs.org/5-support-...led-to-send-an-email

support.toastmastersclubs.org/5-support-...hentication-e-mail-2

Our email addresses are:
michelle@design4dot.com
paul@design4dot.com

If I change my email address from michelle@design4dot.com to my gmail account, it works fine.

I'm happy to go back to my host, but I need more direction.
From what I know, I don't see an error in the admin when I try to send my self a welcome message. It says it successfully sent.

Let me know what else you need.

Thank you.
Michelle

Someone using your hosting company tried to hack our server. I have removed the block for now.

Brian, thank you for reply.
About 10 minutes ago, I sent myself another test and it didn't come through.
Any other suggestions? Should I do something on my end?

I just received some test emails. Hopefully, this is resolved.
woohoo!
Michelle